Specifying allowed client SSH key types that the server accepts

I just struggled with this for far too long this morning on an Oracle Linux box.

If you are running on the same or on any other RedHat based distribution, check that your sshd_config settings aren't being overridden by those of the system's default crypto policies. See the man pages for update-crypto-policies and crypto-policies for details.

/etc/crypto-policies/back-ends/opensshserver.config should show the settings currently being applied by the policy for the OpenSSH server.