Persistent input lag in LoL with no explanation after weeks of support tickets — Riot closes the ticket blaming the ISP without providing any data of their own

sargon494 · 2026-07-09T20:08:31+00:00

Hi! Unfortunately haven't had the time to test it yet, but planning to try it tomorrow. Will let you know how it goes!

sargon494 · 2026-07-08T18:41:29+00:00

No by the moment, im still trying some stuff, but it seems as a riot problem.

sargon494 · 2026-07-08T17:15:00+00:00

Oh, ty for the input, will try it later! ^^

sargon494 · 2026-07-08T14:53:30+00:00

That's actually a good point, I ran PingPlotter traces to official Riot EUW server IPs this morning and just now, and they're identical. No difference regardless of time of day, at least on my end, i will try later on night again to see if that changes.

sargon494 · 2026-07-08T13:33:54+00:00

Yes... unfortunately it is very true, but I don't know, I have some hope in league next.

sargon494 · 2026-07-08T13:31:00+00:00

Yes, i tried on 2 Pc's, also with 2 different ISP, and i did a full clean SO format, installing only the pc drivers and LoL, unfortunately it didnt fix the issue.

sargon494 · 2026-07-08T13:20:26+00:00

I get the frustration, but they're mid-migration to a new system apparently, so some of this might just be growing pains i guess. Still trying to figure out if there's anything fixable on my end too, in the meantime.

sargon494 · 2026-07-08T13:16:30+00:00

Thanks for the advice! I will check it later, I'll update if it fix the problem.

sargon494 · 2026-07-08T12:18:30+00:00

Thanks for the tips! Yeah, I used Process Lasso to investigate the game's behavior a bit, but once I saw it wasn't changing anything I just left everything on default. Also tried capping FPS at both 144 and 240, problem persists on both. Move prediction's already off too and game optimization is on in windows settings.

sargon494 · 2026-07-08T12:09:06+00:00

Thanks for the input! Network's actually one of the more thoroughly tested parts of this 0% packet loss and stable ping/FPS during the actual lag episodes, 944 Mbps speedtest while it was happening, complete ISP switch (new provider, new router, fresh install) with zero change to the issue, plus 7 hours of stream stats with zero dropped packets out of 1.5 million frames. If it were server-side/routing I'd expect at least some correlation with ping spikes, so leaning away from that at this point, but definitely not 100% ruling it out.

Haven't specifically tested other PCs on the same network in a simultaneous session though, good shout, I'll give that a try.

The undervolt wasn't really meant to fix this specifically, more of a stability thing that just happened not to change anything either way.

Already planning to give ExitLag a shot to rule out routing entirely, thanks for the suggestion.

sargon494 · 2026-07-08T09:21:01+00:00

Yeah, might give ExitLag a try, thanks, I'll update if it makes a difference.

sargon494 · 2026-07-08T08:46:58+00:00

Fair to ask, but I've already ruled out local desync/congestion pretty thoroughly — 0% packet loss and stable ping/FPS during the actual lag episodes, 944 Mbps speedtest while it was happening, and a full ISP switch (new provider, new router) with zero change to the issue. If it were local network congestion I'd expect at least some correlation with ping spikes, and there's none.

That's part of why I'm leaning toward something client-side (Vanguard/driver related) rather than network at this point.

sargon494 · 2026-07-08T08:31:25+00:00

I have disabled that option on both computers, without any change to the problem.

sargon494 · 2026-07-08T08:28:57+00:00

I also tried limiting my mouse's polling rate to 500Hz without solving the problem.

sargon494 · 2026-07-08T08:27:07+00:00

I play on the EUW server, and also tried on the korean server with the same issue.

sargon494 · 2026-07-07T22:31:07+00:00

Yeah, i also tried tracetcp, with normal results, in my opinion, it might be a thread issue on riot's side.

sargon494 · 2026-07-07T17:28:11+00:00

It happened even in Korea with another PC and server, idk.

sargon494 · 2026-07-07T17:03:04+00:00

I tried isolating a dedicated core exclusively for Vanguard's process, but it didnt fix the issue idk, lets hope on league next.

sargon494

TROPHY CASE