@skipchang Did you ever follow up on @fd0’s suggestion? The same thing has been asked in Ciphertext verification failed during restore, `restic check` found no errors and I’m just curious.
The cause of your problem is likely what @fd0 said, the file in your repository was for some reason modified (not by restic, so you might want to check your hardware).
I’m looking to mark this thread as solved, but would like to hear how it went for you first.