I have quite some issues trying to RDP Win 10 Pro PC form recent iMac 24' M1.
Using Microsoft Remote Desktop 10.7.6 the only way for this to connect at all was click only "Optimise for Retina displays" under Display settings. Any other settings result in immediate disconnect.
Issue seems to root in inability of the RDP to go Full Screen on the 24' Retina which is expected behaviour.
Once connected, trying to go full screen form Window -> Enter Full Screen disconnects the session.
Are you planning to address this soon?