Hi Bruce,
unfortunately we can’t make use of MS’ RDP client directly in Royal TS. Since we “embed” the RDP session in Royal TS, we depend on their RDP ActiveX control. As soon as Microsoft updates the ActiveX control, the issue will be resolved in Royal TS as well. As mentioned in our KB here Mouse Cursor issue with high DPI in Remote Desktop Sessions the best way to get MS to fix the issue is to provide feedback using the feedback hub app in Windows 10 - or, if you have some sort of support contract with MS, you could also open a case with them.
Regards,
Stefan