Backup hangs and doesn't progress every couple of days

I really like Duplicati and have been using it for years – thank you for that.
Now, I have installed version 2 on a new win10 computer and every couple of days it hangs on a daily job to backup around 15GB to S3.

Symptoms:

  • Message: "Counting (1334 files found, 5.70 GB) " – the entire backup is around 15GB and >10k files.
  • Large CPU load ~40%
  • No progress
  • Quitting and restarting Duplicati doesn’t help
  • Restarting the entire computer helps

Any idea of what I should do?
General question: Is it better / more efficient to split a backup in smaller pieces?

Thank you for your support!