For me it's the opposite. I tried to use nextcloud for years, installing the normal way, and it always broke for no reason. I just started using it on docker and it has been perfect, fingers crossed.
Interesting, when I used docker on a proxmox build, it would give me trouble. Once I installed it the normal way on an Ubuntu build, it was good to go.
I wonder why that is?
Fingers crossed that it continues to work for you in the current configuration!