Would it help to set the battery setting to something like No Restrictions, so that it would keep on running?
If “yes”: Have you got any experience if this would make Bitwarden become one of those “big battery drainers” ?
The phone stays on permanently (a Pixel2xl) except for the odd times I run out of charge and my extra batteries are also out or I don’t have them with me. So as far as I understand it, once the app is open and logged into, it should stay open unless I reboot the phone?
I’ve tried this and have found the same issue as @philip_rhoades - it doesn’t seem to honour the timeout setting on Android. I’ve had this issue on more than one phone (Pixel 3XL and Pixel 4a).