Must use edd25519 encryption keys
Took me ages to realise that you must use an edd25519 key pair when connecting to this AMI. RSA keys will not work with RHEL 9 and derived Operating Systems it seems.
Thank you for your feedback. We were able to connect with an RSA SHA256 key pair when using PuTTY and the last version of this AMI. Please do contact our support (https://procomputers.com/support.html) when you encounter such issues, and we'll be more than happy to help. Thank you again.