I have created a separate issue for the instabilities: App very instable at the moment
So this is only about the “lost” switches configuration which is, as said, a minor bug imo. Still would like to get a quick response as to why this happens.
Only new info I have is that it is reversed with the information shown in the official Hue app: Some accessories show “Not configured in this app” - those who do work in Hue Essentials. Some accessories do not have this message and these are the ones where Hue Essentials does not show the existing configuration (done with Hue Essentials).