High CPU Usage with RDP Gateway

Hi,

Finding after 45 minutes to an hour ASG begins to max out the CPU
This only happens if I connect to servers via a RD Gateway.
If the server(s) I'm connecting to are only direct then it's fine.

Client computer is Windows 10, tried disabling AV completely and still the same.
This was also happening with ASG 2017, upgraded to 2018 and no change.

Any advice would be much appreciated

Thanks