Battery drain on XA2 when not in flight mode

I forgot to turn off the Wifi last night, so I got the graph with 4G and wifi enabled:

It uses the battery much more.

I’m disabling Wifi now.

Btw, I plan to try older versions of SailfishOS, first to get back to a version where I didn’t have these issues (if it’s possible), and second, to try to understand what caused this regression.
I found this GitHub repo, but I’m not sure if it’s legit.
Is there any official way to download an older version? (I was thinking: since there are a lot of point releases, maybe there’s a way.)

Thanks for your help!