Just going to add my experience with this issue in the hope that it may help with a solution.
We have 3 older ATVs running infuse and 1 4K ATV.
This issue has only occurred on the new 4K ATV (twice).
The issue seemed to occur after Infuse was updated.
My 4K ATV is the 32GB model and looking at storage (using TVStorageInfo app), it normally has approx 15GB utilised out of the 29GB available.
Most of this space is taken by metadata, as I have only 2 other small apps on the ATV, besides Infuse.
After the last loss of metatdata, I looked at the storage available, and there was virtually none left, despite me not installing / uploading anything.
After doing a simple restart, the storage went down to very little used (can’t remember exactly how much).
Theory - for some reason, after the Infuse update, it has tried to duplicate the archive of metadata and run out of space, therefore triggering the deletion of the archive.
? When an app updates, does it replicate the archive before deleting the old version?
Hope this helps.