Since installing this version, I’ll be in the middle of working in a Calc spreadsheet and it will close on its own. Work done since opening is lost.
Also, have set AutoSave every 1 min and it hasn’t saved for over 10 minutes.
You are aware of the fact that the ‘AutoSave every …’ option only will save recovery information, not a regular file?
If such an AutoSave took place next time when you start LibO recovery should be offered. If it comes to that you should not hesitate to save your work via ‘Save As…’ in the regular format (.ods).
Anyway: For any new document to work on and not just meant as a kind of notepaper you should choose a name and create the file as the very first step of your work.