Please try removing the TPAMConsole from the Known Hosts on the DPA.
Using Putty - login to the DPA, if Remote Access is disabled, then do this via a direct connection to the DPA.
In putty after logging in - option 4 "Manage Network Settings" then option 11 "Delete TPAM from known_hosts"
You can then reboot the DPA and then test connections via the DPA.
In some cases it may be required the remove the DPA from the Known_Hosts on the TPAM appliance also, this can be done by following the below steps:
TPAM /admin interface - Keys - Manage Host Keys - Select the IP address of the DPA - Click "Clear Known_Host" button.
Then re-enroll the DPA into the cluster and test PSM session behave as expected. More information on enrolling DPA's can be found in the Sys Admin documentation - https://support.quest.com/download/downloads?id=6027521