IMO, in most circumstances of the wifi issue its not because of ax, 2.4 or 5 Ghz, its not an issue with channel, its not an issue with mesh, its not temperature related, its not an electrical issue, etc etc. It’s just a quality issue with the wifi adapter inside the rachio and/or something messed up with its logic. As far as I know a lot of rachio’s logic is processed through their servers, maybe its something to do with that when everybody starts running their schedules for the season bogging down their servers and something inside the units gets hung up and boots it off wifi.
My rachio3, for example, starts having wifi connectivity issues every May when I turn off hibernate mode and activate my schedule. Once it has that logic running, it messes with the wifi somehow. I leave it on all year long and it stays connected to wifi the entire time until I activate my schedule in May. But the weird thing is the connectivity issue only happens from May through June (except for last year it went a little longer) and I usually have my schedule running through October. Last year also had my flex daily schedule’s logic messed up for a couple weeks at the beginning. That added evidence to my idea that something its doing is messing up the wifi connection. When mine goes offline, it doesn’t run any schedule even though its supposed to store something in memory, and has to be manually reconnected. I have to disconnect/reconnect power and then reconnect to wifi. Only device in my house that has an issue connecting and only during a couple months of the year. Really weird. Wish they could make an ethernet module for it.