What are the other wrong and right file sizes? Can you post or convert to hex with Windows calculator?
Possibly they were all truncations at the end, but that wouldn’t be knowable without taking a closer look.
Looking directly on the NAS might also be worthwhile. There have been cases of consistent wrong size depending on what tool is asking. SMB to NAS has been a problem sometimes, for unknown reasons…
If problem keeps happening, you might see if there is another Storage Type you can use instead of File.
Recovering by purging files is probably the best next path to go down, assuming you want minimal loss.
Although it’s not said, this method seems to need bad dblock files completely gone, not just wrong-size.
Instead of just deleting them, you could move damaged files to some folder outside of the backup folder.
list-broken-files is a commandline tool to say what source files are affected. purge-broken-files can then remove their damaged backups from the backup. Assuming you use the GUI, GUI Commandline may be simplest way to do this. The Target URL and database path are already there. You’ll need to at least pick Command from dropdown, and clear the source paths from
Commandline arguments before running it.