Is it possible that you disable pf (only if you are on local secure network) and test it without it?
Could you post complete files /etc/ssh/sshd_config and /etc/ssh/ssh_config for both server and client machines?
How does your .Xauthority file on clent machine looks like? Do you use XDM or equivalent? Do you maybe use full Gnome or KDE? on the client machine?
Can you post the message that you get when you try to log with
Code:
ssh -Y my.account@my.server