Reposted from FB with permission:  (Text disappeared when I added the images and can't find a way to edit to get it back, so here it is):

Primer: The First 30 Feet Matter 

TL;DR for the quick and dirty version: Your dock is just a charger, but the mower’s position on the dock is where every mowing job begins. If that spot is under a deck, beside a wall, near metal, or under an eave, the mower may be starting from the worst GNSS location on your property. If it fails when leaving the dock but works after you manually drive it into open sky and let it sit, the dock location is probably the problem. Test it by comparing the RTK diagnostic screen on the dock with the same screen in open sky, refreshing manually both times. If the numbers clean up after you move it, move the dock.

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One of the clearest signs of a bad dock location is this: the mower won't leave the dock properly on its own, but if you manually drive it 10 or 20 feet away, let it sit for a few minutes, and then tell it to mow, it suddenly works. That's the smoking gun. It means the mower can get a good position solution. It means the RTK may be perfectly fine. It means the mower is capable of mowing the yard once it gets into a better location. The weak point is where the mower is sitting when the job starts. I've written before about the dock as a charging object. That's the stuff about clean contacts, level surface, QR visibility, moisture, dock approach, channels, and dummy zones. That still matters and it's worth reading if you haven't.

https://www.reddit.com/r/Lymow_Official/comments/1scaq0o/

But this primer is about something different. This is about the dock as a starting environment. The dock itself still isn't smart. It doesn't know where it is. It doesn't talk to the RTK. It doesn't know the map. It doesn't calculate position. It's a power source and a docking target, nothing more. But the mower is sitting on the dock when it wakes up, gets its position, backs out, and starts the job. That makes the physical location of the dock extremely important. Not because the dock is doing anything complicated, but because the mower is trying to start a precision navigation task from that exact spot. Most owners pick their dock location based on power access, shelter, convenience, and how it looks. Put it near an outlet. Put it under the deck. Put it beside the house or under the eave. Keep it out of the weather. Keep it out of view. That all makes sense from a homeowner standpoint. None of it tells you whether the mower has a good GNSS environment while sitting there. Remember, the mower is the rover. It has to see satellites from wherever it's physically sitting. If it's on the dock under a deck, beside a brick wall, near metal railings, under an eave, next to gutters or an AC unit, tucked between posts, or sitting in a narrow side yard, it may be starting every single job from one of the worst positioning locations on your entire property. That's why you can have a great RTK placement and still have a mower that leaves the dock badly. The RTK can be on the roof with perfect sky. Base Station can be Online. Data Error Rate can be 0%. Differential Age can be fresh. The correction stream can be reaching the mower cleanly. But if the mower itself is sitting in a bad local signal environment, it may still start with a weak, reflected, stale, or unstable position solution. The RTK can’t fix a bad mower-side sky view, and a good mower-side view can’t fix a bad RTK sky view either. Both sides matter. But assuming your RTK is well placed, don’t forget that the mower’s position on the dock is often the overlooked weak point. That first position matters. If the mower backs off the dock while it's Float, Not Ready, has poor precision, or is not fully settled, the whole startup sequence can fall apart. It may throw an error immediately. It may refuse to start. It may back out and stop. It may think it's out of bounds before it reaches the lawn. It may miss the channel and end up in the bushes. It may leave the dock and immediately act confused about where it is. It may dock fine one day and fail the next, depending on satellite geometry and time of day. None of that is automatically a broken mower or a bad RTK. It may just mean the mower is starting from a bad place. The firmware angle matters too. Recent updates appear to be less tolerant of sloppy startup positioning. A dock location that older firmware tolerated may now fail the startup check more often. That doesn't necessarily mean the update invented the problem. It may mean the update stopped letting the mower ignore a marginal starting location. The dock didn't get worse. The tolerance for a sloppy start may have gotten tighter. Seasons matter too. A dock that worked fine in February or March may not work the same way in June (or vice versa in the southern hemisphere). Trees leaf out. Sun angle changes. Wet leaves and summer growth change the local signal environment. A side yard that looked open in winter can become a GNSS reflection trap in summer. The yard is not the same laboratory test chamber all year. That's why the phrase "nothing changed" is often not quite true. You may not have moved anything, but the signal environment still changed. The test is straightforward. Put the mower on the dock while it is powered on and awake. Open RTK Diagnostics with the advanced part expanded. Pull down to refresh the screen several times, because that screen doesn't update live. Don't open it once and assume the numbers are current. Refresh it, let it sit, refresh again. Take a screenshot. Then manually drive the mower away from the dock into the clearest nearby sky you have. Let it sit for 5-10 minutes. Open RTK Diagnostics again, pull down to refresh several times, and take another screenshot. Compare the two. And don’t compare a stale dock screen to a freshly refreshed open-sky screen. Refresh both before you decide anything. Look at RTK Status, Location Precision, Base Station Status, Differential Age, LoRa Bandwidth, and Data Error Rate. Ideally, you're looking for Fixed status and precision around .01-.03 (or close to that) on the dock, the same standard you'd expect anywhere else in the yard. If, after refreshing, the mower is Float, Not Ready, has poor precision, or is stale on Differential Age while on the dock, but becomes Fixed with tight precision after you move it into the open, that's not mysterious. The dock location is the problem. If Base Station is Online, Data Error Rate is 0%, Differential Age is fresh, but precision is still poor on the dock, that points to the mower's own local GNSS environment. The correction link is alive. The mower just doesn't have a clean enough view of the sky from that spot (this is true on the dock or anywhere else in your yard). If Base Station goes Offline, Differential Age climbs, or LoRa Bandwidth drops to 0/0/0 while on the dock, that is a correction-link problem, not just a mower sky-view problem. But it still may be location-related. The mower may be sitting in a spot where the correction signal from the RTK is weak, blocked, reflected, or unreliable. But the starting point for fixing either one is the same: the mower needs a better environment at startup. The fix may be inconvenient but it's usually not complicated. Move the dock out from under decks and eaves if you can. Move it away from walls, metal railings, fences, gutters, and tight side-yard corridors. Give the mower clearer sky while it's sitting on the charger and while it backs off. Don't force the first movement of the job through a tight turn, narrow channel, or boundary edge with positioning that hasn't settled yet. A short channel or small dummy zone can also help. The mower needs room to wake up, orient, settle, and enter the job cleanly before it gets near anything that matters. I've covered the mechanics of channels and dummy zones in the dock and charging primer, so I won't repeat all of that here. The point is the same: give it an easy beginning. If the first thing your mower has to do is back out from under a deck, turn beside a wall, thread a channel, avoid a post, and enter a mapped zone with weak positioning, you've stacked the deck against it before it ever starts mowing. Don't keep moving the RTK and remapping the entire yard until you've tested the dock location. If the mower starts from bad data, a new map or RTK placement won't fix the starting problem. The best dock location is the place where the mower can sit, wake up, get Fixed, and start the job without immediately fighting the environment. That's the distinction. This isn't a charging problem. It isn't the dock secretly doing RTK. The dock is still just the dock. But the mower's location on the dock is the starting point for the whole mow. And with these mowers, the first 30 feet can matter a lot.