I'm trying to setup a backup job with backuppc using rsync and PKA (public key auth over SSH). I use the same process on all our Mac's but half of them PKA works and half of them it does not work and prompts for password when trying to SSH from the server to the Mac. However SSH PKA from the Mac to the server works on every machine perfectly.

Here is the guide I used to do the key exchange.

Here is the SSH debug viewer when trying to ssh from the server to the Mac.

I have retried the process several times with the same outcome. I have verified permissions on all the directories, I have also copied the ssh config over from another working machine to the non working Mac's and it still does not work.

Any help here would be awesome.