Is Xfce the desktop environment you installed and wish to use?
If so, note that xfce 4.20 (on f43) is not Wayland enabled and uses Xorg instead.
I use xrdp all the time on F42 and just tested with F43 and it works just fine.
In /etc/xrdp/xrdp.ini, I enable Xorg and disable VNC:
; Some session types such as Xorg, X11rdp and Xvnc start a display server.
; Startup command-line parameters for the display server are configured
; in sesman.ini. See and configure also sesman.ini.
[Xorg]
name=Xorg
lib=libxup.so
username=ask
password=ask
ip=127.0.0.1
port=-1
code=20
#[Xvnc]
#name=Xvnc
#lib=libvnc.so
#username=ask
#password=ask
#ip=127.0.0.1
#port=-1
#xserverbpp=24
#delay_ms=2000
; Disable requested encodings to support buggy VNC servers
; (1 = ExtendedDesktopSize)
#disabled_encodings_mask=0
; Use this to connect to a chansrv instance created outside of sesman
; (e.g. as part of an x11vnc console session). Replace ‘0’ with the
; display number of the session
#chansrvport=DISPLAY(0)
I also add the file ~/startwm.sh to the home directory of the user logging in via xrdp: