MFT (9.7) SFTP SSH Connection error

One of our external partners has recently switched to a new FTP server. We currently have a virtual folder setup in MFT to remotely connect over SFTP using user credentials (username/password). The user credentials have not changed so all I have had to change is the server name in the SFTP URL.
Unfortunately when I click on the ‘Test connection’ button I just get the error : com.maverick.ssh.SshException. I am able to successfully connect to the new FTP server using a Filezilla client installed on the same server. However, I am prompted that the server’s host key is unknown and I have to manually choose to trust this host before the connection is established Is this error caused by MFT not trusting the server host key? If so how do I get MFT to trust this key.

Hello Richard,

Please share the MFT fix level and ActiveTransfer.log

Properties.cnf file from