Adding temporary users to RHEL8 machine is not working (key not accepted)

While attempting to grant access to Adam as part of https://github.com/adoptium/infrastructure/issues/3929 it was observed that key-based authentication was being rejected for normal users. Since the admin team's administrative logins, and the jenkins server is able to log in over ssh, it is not obvious why but this should be investigated and resolved (Noting that using my key on Adam's account was also failing so it was not specific to the user's client)

Start by reproducing the rejected key-based SSH login for Adam on the RHEL8 machine, comparing it with the working administrative and Jenkins logins. Investigate the account or host authentication configuration; done means a normal temporary user can successfully log in with their key.

Written by the indexing model from the issue text.