Now it happened three times so far, and I came to the conclusion that the hub has problems connecting to my router. The router transmits with the same network id on both the 2.4Ghz as the 5Ghz band, and has a feature called smart connect so when I walk with my phone out of range of the 5Ghz network it automatically switches to the 2.4Ghz. Great feature, but when that is enabled, the Hub doesn’t want to connect. It doesn’t see the network at all. I have to disable smartconnect and the 5Ghz and only then the network shows up. Once connected I can enable 5Ghz and smart connect and the hub stays connected.
My suspicion is, that there is secretly a 5Ghz antenna in the Hub, Weatherflow doesn’t use 5Ghz, but perhaps the chip does and it searches on both bands, finds the 5Ghz one, and the firmware in the hub ignores it. I think it needs a bit more attention to search only on the 2.4Ghz, or at least don’t ignore a 2.4Ghz network when there is a 5Ghz network with the same name.
Of course this is just speculation on my side, but if possible, someone should look into it.