I noticed a problem when using Microsoft Remote Desktop on OSX 11.4 on a Macbook Pro M1 where if I take a screenshot within remote desktop using the Mac screenshot tool (sending the screenshot to the clipboard), the screenshot is not available to paste within remote desktop. If I minimize the remote desktop session and go back to the Mac side, I am able to paste that screenshot though. So it is just a problem of it being made available to to the remote desktop clipboard.
Funny enough, if I use the same screenshot tool on the Mac side to take a screenshot, and then go back into remote desktop, I can paste that screenshot without issue. So the problem only seems to be when both taking a screenshot and trying to paste it within the same remote desktop session.
My only workaround at this time is to select the screenshots to be automatically saved as images to the mac side desktop so when I screenshot in remote desktop, it does indeed work and saves the image file automatically on the Mac side. It's annoying because I then need to copy/paste that file over to the remote desktop side and then insert it where I need it as opposed to being able to quickly just take a screenshot and paste it in.