I obtained the answer on Discord, so I thought I’d share it here in case anyone ran into the same issue.
The sector trailers for the Mifare Classic 1K: blocks 3,7,11… 63 need to be rewritten first.
In my case, blocks 0 to 7 had an auth error, so I need to re-write blocks 3 and 7.
After obtaining the keys to those sectors with: hf mf autopwn
I re-wrote the sectors using: hf mf wrbl --blk [block] -d FFFFFFFFFFFFFF078069FFFFFFFFFFFF -k [key]
After doing this, I’m able to re-write to the fob again with: hf mf restore
No more auth errors.