Restoring blocks from a backup makes a void

[ToastyRavioli]

when restoring a set of blocks from a backup, it simply fills that area mostly with air, with some blocks leftover, like random sections of andesite or stone.

command I ran:
/bm restore blocks -60 0 137 -84 30 91 2020/1/12-24:45:49
I tried using different backups, all to the same effect.
Does anybody know whats happening here?

[Fadenfire]

Does it give you any errors when you run the command? You should also upload the log.