Update
I continued looking for help on the issue but find no satisfying fix.
I could restart my service and brace until the next crash but I choose instead to switch to an external service provider (Cloudamo). Things works quite fine since then.
I think even if installation and setting up of NextcloudPi is possible for person with low skills the maintenance and inevitable bugs are far from easy to solve.
In my opinion to use NC with low computational skills you have to :
- Start small with simpler services and step by step increase the complexity of the service in use (host a website, a mail platform etc.)
- Accept a budget for external maintenance help (use an external provider, pay people on NC forums to help you…)
If you have a problem similar to mine, sorry the fix is not in this topic but it sounds like there is a similar issue here :