I can access Microsoft Remote Desktop when I am at home connected to WIFI/LAN. However, I intend to access my Windows 11 PC remotely using OpenVPN. It seems that Remote Desktop over OpenVPN does not work although I can connect to OpenVPN successfully.

I read the solution in community and I still can't find the solution.

My router is provided by Starhub ISP (TP Link Archer BE810v/BE22000).