I have just recently installed the Buster backport on an old VAIO box. It is the only OS on the machine. I also installed xrdp and it initially worked fine a couple of times with both root and non-root accounts from my Windows 10 box. Now when I try to directly log into Gnome as root at the box itself it says "Sorry, that didn't work". I'm sure the password is not the issue, because I can still log in as root over rdp from the Windows machine. Also, I am not sure if this is a related issue, but the situation is reverse with the non-root user. With that one I am able to log in from the box itself but when I try to open an rdp session, it seems to log in for a moment only to immediately close the connection with no errors. ssh seems to work fine with the non-root user. I'm generally new to the *nix world and don't know my way around.