Microsoft RDP through Sophos Client to site IPsec VPN

Hello

I am using XGS136 (SFOS 21.0.0 GA-Build169), I have created Client to site IPsec VPN connection, the client can access the network normally and all is good, however each time the users tries to open Microsoft RDP ( Remote Desktop Connection) to a device in the network through the VPN they get "An Internal Error has occurred"

knowing that while using the LAN normally the RDP works fine

I have checked the log and didn't find anything related to this 

please help

Thank you