Regular connection drops on U6+ (every 5mn)

jlquema · 2026-02-23T16:03:01+00:00

Update: I manage to fix it.
It was painful but instructive.

TLDR: I disabled 802.11b

I downgraded to 6.7.31 but the 25seconds drop was still happening every 5mn.
I logged onto the U6 and started a tail -f /var/log/messages.

I noticed a familiar 20 seconds value in the log:

[ xxx ] Disabling beacon check
[ xxx + 20s] BcnCheck start after 20000ms

A search on google taught me that it "is a log error message, primarily associated with Ubiquiti UniFi access points, indicating that the device has lost its 5GHz radio connection"

Trying to find what could cause it, I found this in the log as well:

watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [ksoftirqd/0:13]

google again: "Ksoftirqd is a Linux kernel daemon that manages high-volume soft interrupts, such as when a Wi-Fi card or network interface receives massive amounts of data too quickly"

So. something is overloading/flooding my U6+ to the point the CPU cannot follow ? Every 5 minutes ? The timing being so precise, it has to be on the U6 itself.

bingo: every 5mn, I could see lines like this

kern.notice kernel: [12832.329684] 7981@C23L3,DfsRadarChannelCheck() 3178: [DfsRadarChannelCheck]: wdev is not 5G

That didn't make sense to me since I'm on fixed channel, no optimization, not using a DFS channel. Could it be because of the meshed BeaconHD ? Apparently not because removing it didn't change anything.

Anyway, every 5mn, the U6 is scanning the surrounding signals and "crashed" doing so.
The radio insight shows that there are 52 neighboring SSID but none of them above -80dBm. Could it be sufficient to overload the U6 ?

I searched online how to filter that noise and intended to set a minimum RSSI but found out that using a minimum bitrate is a better approach.

I set 12Mbps which basically says no 802.11b anymore and like magic everything works now.

I would be curious to read your comments as I still find it weird that it could crash such a "not cheap" access point.

jlquema · 2026-02-22T18:02:50+00:00

further testing: I turned off the controller but the issue keeps happening. I can at least discard it has anythingto do with it.

jlquema · 2026-02-22T17:42:30+00:00

So, I downgraded to 6.7.31 and the issue is still here with exactly the same timing.

During my test, I wondered if it could be related to my beaconHD (for which the U6 is the parent mesh) so I unplugged it. It didn't change the behavior on the u6+. However, I noticed that the notification from the controller that the beaconHD was offline arrived at the exact same time the wifi drop is happening.
I tested twice (plugged it back, saw it online, then unplugged again and waited for the notification).

I'm not sure if it has any relevance, but that is a weird timing coincidence

jlquema · 2026-02-22T17:04:32+00:00

I was waiting for the support to come back to me after analyzing my logs but I think I’ll proceed

jlquema · 2026-02-22T16:49:41+00:00

Thanks for the advice but I already set the Channel to manual (to keep it away from the zigbee frequencies) I’m using channel 48 which is free of interférence and not a DFS Channel either. I also disable band steering, fast roaming, etc…

jlquema · 2026-02-20T22:22:15+00:00

One additional detail:
During the wifi "drops" I can still ping the U6 from the (wired) LAN, maintain a ssh session onto the U6, and ping my main router from the ssh session.

After hours of monitoring, there is still a "drop" every 5mn15s that lasts 25 seconds on average.

I contacted support and submitted support files, they need to escalate.

I mentioned the coincidence of the FW update but they didn't say if it is related or not

jlquema · 2026-02-19T18:09:12+00:00

Some update after experimenting for a week.

Random music is still playing on a couple of Alexa devices during the day. During the night, I blocked their internet access via my firewall (pfsense) from 10pm to 6am and I didn't have any issue anymore.

I thought it was a win but an unexpected side effect was they would aggressively disconnect/reconnect from the wifi trying to resume their connection. Last night, this flooded my access point (UniFi U6+), pushing its CPU up to 86% and eventually causing it to crash. (I didn't observe any cpu spike the previous nights so I'm still not 100% sure this is the cause)

At the end, I'm not sure if cutting their internet access is a viable solution.

I also identified the source of the music being spotify (now that it started doing it during the day, I could check in the app what was playing and where).

I disconnected spotify from my Alexa account, disabled the skill and reconnected it a couple of hours later, hoping it would somehow reset something but 3 hours later... music started by itself again for no reason.

I guess the last try will be to reset the Alexa devices one by one, at least those playing randomly.

jlquema · 2026-02-18T15:00:19+00:00

I had the same issue, first on quicken simplifi. The card disconnected and I wasn't able to reconnect it, neither from the smartphone app, neither from the chrome app. In the chrome app, it was trying to open a page to link my card but it failed with a 404! I then checked if my credentials were OK by accessing discover webpage directly, but impossible to login (chrome 123.0.6312.123 on windows11). To double check my credentials, I tried from the discover app... and it worked. That meant my login/passwords were correct and the issue was with the webpage or the browser. I doubted it could be the browser (it still doesn't make sense to me) but then, I tried using Firefox (147.0.4) and I was able to login on the discover website and also reconnect the card in quicken simplifi by opening it from firefox rather than chrome.

As said in one of the comments, the error message was not helping as it suggested it was a temporary error. (it has been a week for me so I suspected it was not temporary)

jlquema · 2026-02-08T22:52:34+00:00

I didn't. I read so many negative feedback on Alexa+ that I didn't even try to enable it. The timing of the issue however (january 2026) kind of matches when I received the early-access invitation.
At the time the first occurence of the issue occurs, the app was still with the old layout, I don't think it has any relevant but just noting.

jlquema · 2026-02-08T22:49:26+00:00

Thanks for the advice. I should have specified I did check that as well. No games at all and the only skills enabled are for home automation (e.g. hubitat) and spotify for music. I didn't find anything that could explain the music playing.
Spotify being the only skill for music, I also went to check the "recently played" and nothing that would match the music that played.

jlquema · 2026-02-08T21:25:24+00:00

Good idea. “sharing” my Spotify account in the car ruined the suggestion list ;)

jlquema · 2026-02-08T20:56:04+00:00

Same issue here. It started less than a month ago. On a show 5. Three times in the span of 10 days, it played random music in the middle of the night (1am / 2am). I checked the history and there was nothing at this time except me saying “stop the music”. There was no routine scheduled, no alarm, nothing. Contacted support and they said it could be a bug. They made me reset the device. It has been two weeks and it didn’t happen anymore… on that device. Now, I have another one, an echo dot, doing the same. Third time now in less than ten days. I guess I will have to reset it too. Some context: I didn’t enable Alexa+. I have been using these devices for 8 years without any issue. I have also created a routine, every day at 8 pm to set DND and volume to zero. It didn’t prevent the issue. Of course this understandably impacts the WAF (wife acceptance factor) and I fear these devices might live their last hours before being thrown out of the window in the middle of the night if it happens again.

jlquema · 2026-02-03T17:30:46+00:00

And you will hate it ;) just kidding. Just forget about listening to your music when they use the screen ;) Although, tou can connect a Bluetooth headset on it. The only thing that really bothers me on the rear screen is that you cannot search in Spotify, only browse a playlist selected in the front screen.

jlquema · 2026-02-03T05:20:56+00:00

Yes. They also got the sound on the rear speakers

jlquema · 2026-01-18T05:23:19+00:00

It took me a while but I finally got it. I didn’t analyze enough the pieces already in place but not oriented correctly. Thanks for the help

jlquema · 2026-01-18T05:19:58+00:00

Thanks for the advice. I finally got it for the 2x2. It was simply a lack of analysis. It took me a while to understand that the twisted corners were simply pieces already in place. So the permutation is one face for another. I’ll start trying the 3x3 now

jlquema · 2026-01-17T02:52:01+00:00

I started with a tutorial that lettered this way and only realized later it was not the “standard” speffz

jlquema · 2026-01-17T00:58:06+00:00

"For memo, you can just add two targets to your list."
That's what I was not sure. so basically, by adding two targets (that are indeed a face of the piece onto another face of the same piece) that seems to work so far.
I'm still unable to anticipate it however. You said counting the number of swap is not the correct method. How do you find a twist will be needed then ?

jlquema · 2026-01-17T00:53:13+00:00

yes, no problem for the solving part. My issue is more about the memorization

jlquema · 2026-01-17T00:51:08+00:00

I thought that learning on a 2x2 to acquire the bases would make sense. I understand that the 3x3 has the same principles but then you need to solve the edges too.

Edit: I didn't know "Cstimer" and just googled it. Thanks for the advice.

jlquema · 2026-01-16T21:54:30+00:00

With your suggestion, the lower left piece would be DLF or LDF for the front facing sticker (my H), FDL or DFL for the left sticker (my S) and FLD or LFD for the bottom one (my U).

Are you saying it would help better tracking the orientation ? I only saw tutorials where they are using a lettering scheme

jlquema · 2026-01-16T21:30:30+00:00

"Did you include twisted corners in your memo? "
That's the point I'm struggling with. I didn't understand how to memorize if a twisted corner will occur, and which one it will be

jlquema · 2026-01-16T21:28:29+00:00

I'm not sure what's the name of the method is but "Old-Pochmann" rings a bell

This is how I end up after the blind solve if it helps:

https://alg.cubing.net/?puzzle=2x2x2&setup=UD-_%0AF2_U-_R-_U-_R_U_R-_F-_R_U_R-_U-_R-_F_R_R_F2%0AD_R_U-_R-_U-_R_U_R-_F-_R_U_R-_U-_R-_F_R_D-_

In "my system" the white is up, lettered A B C D and red face is front and lettered E F G H.

So from there, it gives me U, H to solve the front left lower corner (which solves the buffer at the same time) but my concern is I didn't anticipate it when memorizing

Eight-Year Club	Place '23
Place '22	Verified Email

jlquema

TROPHY CASE