While I haven't had a chance to change my systems to legacy capture mode, I can confirm that I'm seeing the same issue though not exclusively on AMD graphics. I believe, at least in my case, it happens when the monitor connected to the remote machine is turned off. I don't mean the monitor has entered sleep mode. I mean the power has been turned off to the monitor. In this situation, I can connect but the display is black. No interaction with the system will get it to start working.