I am experiencing this exact same issue as well ! I am running on iOS 15. The issue is on my iPad Mini. The battery drain is is taking at least 70% battery each day. I cannot even remove the "HOME" from my HomeKit... when I click on "Remove Home", it doesn't really do anything. Please Apple, can you look into this? My iPad is effectively unusable now...

I am experiencing this exact same issue as well ! I am running on iOS 15. The issue is on my iPad Mini. The battery drain is is taking at least 70% battery each day. I cannot even remove the "HOME" from my HomeKit... when I click on "Remove Home", it doesn't really do anything. Please Apple, can you look into this? My iPad is effectively unusable now... — EmptyHugo less than a minute ago

Just to give an update to all, I tried all previous suggestions and nothing worked. I managed to fix it by wiping out my iPad to factory settings and NOT RESTORING FROM CLOUD. So essentially it was if I had a new iPad.… only then did the battery drain get fixed and I am happy to report my iPad now lasts as it should