When I'm starting a backup at the closing of lightroom, the catalog which is saved is the the catalog when I have open lightroom without the modification I have done during the session. In the example, you can see a zip file à 12:03 but the file inside is at 11:31... all the work I have done during half an hour is not backuped...
Not sure I understand.
Your working catalog file last modified time is 11:31
Your backup file time is 12:03
That is 32 minutes after the last modification was added to the working catalog file.
How do you know the last edits weren't recorded?
I know because I've just imported 60 files just before and at the opening of the backuped catalog there are not inside...(I have an automatic copy of the backuped catalog on a second computer (laptop) )