You might have done something right, or stopped doing something which was wrong. But it’s good it has been okay for the last three days. Keep it that way.
Personally I do not trust power banks. They are for emergency charging of your device, and may not provide the steady and dependable current as plug-in chargers in my opinion.
Good luck with it!
P.S. Maybe don’t use power banks for a few days and put them into the picture later to see if by any chance it goes down the slope again?
Charging sometimes stopps working also on my GS6:
Plug in the charger (regardless what model or speed or if it’s a PC port) and it lies “(fast) charging” but percentage continues to go down.
Remedy is to do a reboot. But mine never crashed or rebooted itself, it runs very stable.
My assumption is that this happens after using the USB port for any kind of data exchange but I have not yet scientifically verfied this thesis
My asumption is reboot or crash are related to anorher issue regarding murena workspace sync.
Another subject for another topic but after a month I succeed to sync murena.io account with my phone for backup and notes (still have notes unreadable time to time) and then is the starting point for stability.
Your choice, I have been using Avast which I had for years on my PC and used on previous and the current /e/ phone. It is free, but you might find other ones with maybe free trial period… you don’t need to keep it. Personally I would like to rule out malware/virus option if I were you.
The phone was unusable, rebooting all the time, and decided to setup an old LG G3 with Lineage.
I switched off the terminal, extract the sim, and switched on again in order to extract some minimal set of files. Now, the device is on, without SIM and Wifi connected, half an hour, more or less, any reboot until now. I’ll try to update /e/ version.