Can't connect via SSH after replacing Dropbear with OpenSSH

Had been connecting fine with the default SSH client using root@ and a customized password. After replacing Dropbear with OpenSSH using dietpi-software, the same credentials no longer work and result in “permission denied, please try again” error. I’ve tried many other default credentials too but none work.

Did you try to login with the dietpi user instead, so you have access for debugging?

Also please add some information about your system as asked in the template you got when starting the post.

Maybe, on client side the know host file would need to be updated as the SSH server fingerprint changed.