@David-TP Hi, I changed the DNS as advised to 8.8.8.8 and 8.8.4.4. Since then the disconnections do not happen as often as before, bit STILL 1-2 times a day. So unfortunately NO definitive solution.

@Gatriel just to say in my case I also have a mixed network with X90 and M9+ decos, but the X90-ies keep disconnecting, not the M9+´s. I also have no wires, all WIFI.

@LazyBrewer how do you downgrade the firmware on the decos? thx.