Duplicati keeps running but just stops backing up

I’m running a Duplicati server process on a Mac started from a LaunchDaemon. I created a backup that backs up some 180GB of data in 170,000 files (Photos Library). That works fine, but twice now I returned to the machine how it is going (should take about 2.5 days), but twice it seemed stalled. the Duplicati server process was running, it had some 20 threads, but it did not do anything. It took 0%CPU and did not send anything over. What I can do at a moment like that is kill the server and restart it again. It will then verify the backend (fine) and start again with the whole set (which of course goes pretty quickly at first as nothing has changed and needs to be sent).
Th efirst time it had run for a short while until it stalled. The second time it had used 2 hours of CPU time over the night but had stopped after backing up 35GB or so. There is no logging that I can see. Anything I can do to find out what is happening?

There was no logging in the main UI menu “Show log” -> “Live” -> “Profiling” section?

I did look at that at some moment but not during that issue. I’ll check later if it happens again. Is there a way I can get that logging outside Duplicati (written in some sort of log file)?

Try the --log-file and --log-level parameters.

The backup was corrupted somehow (no idea why or how) but repairing the backup fixed it.