Recurring restore fails once every 7-8 occurence

I have two SQL Server 2017 running in the same network. I am taking a full backup of a database, simple recovery mode, and transfer the .bak file to the second server. On that second server I restore the backup. These tasks are running daily, but once every 7 or 8 days I get a 3013 Error that the server cannot find the file specified.
The copy is made by a .bat file run by Windows task scheduler, and the file transfer is always done when the restore starts, even on the days the error pops up.

Any help would be appreciated, I've been looking around for a while and did not find anything resembling this case on the web.


Does your copy process rename the file at any point? I'm presuming that your restore task expects a fixed backup file name, but does your backup process always write/overwrite the same file name each time?

Yes the backup is always under the same name and no rename operation is done.

I've noticed after the job fails that the next successful restore takes much longer, like 8/9/10 hours vs. 11-12 minutes prior. If I had to guess, I would say that there's a longer backup process occurring when it tries to copy the backup file and it hasn't completed by the time the restore job kicks off. It's possible there's a lock on the file that makes it look like it's missing or unavailable.