RDP via TS gateway does not work

Hi, I have the latest RDM installed and am using the latest Microsoft RDP client release. I have a number of file-based RDP sessions that connect via a terminal server gateway over the internet, with a trusted root certificate from our company. As a standalone file, connectivity is fine. However, if I try to import the session, it does not work. I have verified that all the correct options are set in the terminal server gateway section of the session, but no luck. Any ideas?