They all just disappeared from the app. 
Is this expected behavior?
Привіт.
When you reset the M2 gateway to factory settings, it completely clears:
all Wi-Fi settings,
the account it was linked to,
and most importantly, the list of all connected sensors/devices.
That is, the sensors (sensors, relays, buttons) will no longer be “linked” to this particular gateway.
They will have to be added again through the application - start the pairing procedure for each device.
Hello @RunLikeAnAntelope
If you just wanted to reconnect your m2 to the app, you had to reset the network (hold the button for 10 seconds), this would reset the network and the devices would remain when reconnecting. Unfortunately, after a factory reset, everything is deleted, now you just have to re-add everything again.
So I moved the M2 to the location in my house where the router is located so I decided to connect it to ethernet. When I did that it did not switch off wifi and to ethernet. I did the 10 second reset and that didn’t change anything. So I did the 10 press factory reset. Unfortunately. It doesn’t really make a lot of sense to me that it would delete every Aqara item in the house. But oh well. I have added them all back. BUT…the M2 is still connected to wifi. The factory reset did not even fix the issue. Have any ideas why?
Hello, try disabling WiFi 5 on the router and leaving only 2.4 mode.
You can also use an internet cable directly to the router. For binding, and then via the WiFi.