Can't maximize RDP sessions with internet explorer - APM

I see a few similar posts on here about this but no definitive answer. I have Microsoft Remote Desktop shortcuts on my APM and they connect fine and maximize, but if you exit full screen, then it locks the screen to a small size. You can't resize or even maximize again and the maximize button becomes greyed out. Pretty unusable after that point. I thought this might be a bug when I was running 11.4 but I have upgraded to 11.6 and have the same issue. Anybody had the same issues and know how to fix this?

Thanks