Public Key Auth not Functioning

I have been using WinSCP for about 2 years now and the public key authentication has always been going well until recently where it seems to just outright refuse authenticating me using the Key I've been using all this time. The key still authenticates me properly in both PuTTY and Termius.

Attached is the log file generated by the session.

Your server might got updated and now requires ssh-rsa2:

Try upgrading to WinSCP 5.20 beta as it includes:
Issue 1952 – Support rsa-sha2-256 and rsa-sha2-512 SSH public key algorithms

I was having the same problem. I recently upgraded my server to Ubuntu 22. The key was working fine in PuTTY, but not in WinSCP. Upgrading to the 5.20 beta fixed the problem.