I'm on Debian but have been using GNOME with its built-in RDP server since it's Wayland compatible.. But before I did that I had also set up XRDP so here's a few ideas :)
I just installed Debian with XFCE. I installed XRDP but for the life of me I cannot get it working.
Are you using XFCE with Wayland or X11? XRDP currently only works with X11. Make sure the user you are using to RDP with is able to log in normally with XFCE + X11 before attempting RDP.
Also RDP logins only work with Linux users that are not currently logged in at the desktop so make sure you're logged out before testing.
Also double-check that the xrdp.ini file looks right, particularly the incoming port it is configured to use. (on Debian it is in /etc/xrdp/xrdp.ini). When I initially configured XRDP the port setting was strangely configured, it was set with port=vsock if I remember correctly and that wasn't working.. I had to change it to a regular port number. Also consider changing the port number if necessary, I had to change mine but only because Gnome's own RDP server was already using the default port 3389. (if you change xrdp.ini settings make sure to restart the xrdp service)
Also double-check that the XRDP service is active and running (sudo systemctl status xrdp) - on my end the service would stop running when the port number config was wrong which meant it was no longer listening to incoming connections.