Yep. Up to the last instruction. Flashed eu firmware, flashed pixel rom, cleared cache, reboot.
I maybe cannot express this enough, but i can tell you how it can be recreated, at least in my end.
Go to settings app, tap on battery, swipe to go to the recent apps. Then, the settings app will not go to the recents and ‘join’ the others and will stay there.
Moreover I saw that If I leave the app there, it will crash after a while. So far its happening on the Settings app, and on the Play Store as well.