ValheimPlus backups creates zipped file, then kills it

OS Name/Version: Windows Server 2019

Product Name/Version: AMP

Problem Description:

I have a ValheimPlus server running perfectly on a Server 2019 dedicated VM.
AMP is installed with the very latest (at the time of my writing) version:

When I create a backup for AMP, it is created without issues and I see it both in the list of AMP backups and as a zip file in the backup folder.
If I instead run a backup directly on the ValheimPlus instance, I can see that it is working and that it is writing the temporary .zip file in the backups folder. Yey, ss soon as the backup process is completed, the temporary file disappears and doesn’t come up as the completed .zip. Also, there is nothing listed in the backups.

In the log file there is only this timestamped entry, with nothing more to it:
[11:21:57] [System:gameadministrator Activity] : Creating Backup: Test

The user has full access permissions to the backup folder. Other than that, I can’t really think of anything.

Any ideas?