I am using Android 10 and the app version 2.15.15-beta
When I turn off the WIFI it takes a long time for the app to realize that I am not on WIFI and it needs to connect to the cloud
Sometimes the connection is not done automatically so I have to close the app and run it again X3 times
The app should receive a signal from the device when wifi is switched off. Maybe the mobile connection just needs some time to connect after turning of wifi.
Can you post a log of the app and say when exactly you turned off wifi?