While recording a new HTTPS virtual service using DevTest Portal, it is not possible to set the target port as 443 or 8443.
Even when the option to use SSL is enabled, the Portal sets the port back to 80.
This is a known issue with DevTest on release 9.1.
This issue is fixed in DevTest 9.5.1 and later releases.
There is a patch with a fix for DevTest on release 9.1.
To get access to this fix, please open a support ticket and reference the case number DE280118.
You can open a support ticket via CA Support Online or call 1-800-225-5224.