Not all, but several. At first I thought it was because I was in full screen mode, but even when I resize the RU box down to 1/4 of my screen it keeps happening.
Maybe it's due to the version of 10... I know some of the machines are on the newest update, while others are not. But I'm not sure which are which. I only remote in when needed and most of the time someone is there, so I'm not even dealing with the login screen, making it harder for me to be sure which machines have the issue.
When I connect to a 10 machine that is already at the Desktop it's fine. But if it's at the lock screen, the drawing is so slow that I can't even get the password entered. I click on the screen to get it to bring up the password box and by the time I can see it I can't type, because the remote machine has already timed out and is drawing the lock screen again.