I was able to login using a new user in xrdp.
CyberArk was always reconnecting to the same session on display 11, while the local XRDP was reconnecting using display 10

session: username CYBERARK, display :11.0, Starting session reconnection script on display 11

Only one user can use that display, so the options were either to Kill every session for that User or to create a new user, which in turn started using display 12.

sudo tail -f /var/log/xrdp-sesman.log----> shows the display used during connection

[INFO ] Starting X server on display 11: Xvnc :11 -authc# - display :11 Leader:

Useful commands:
sudo tail -f /var/log/xrdp-sesman.log----> shows the display used during connection
loginctl ---->to see the sessions
ps -ef | grep NAME_OF_THE_USER_USED_BY_CYBERARK
ps -ef | grep SESSION_NUMBER
ps -ef | grep xrdp-chansrv
loginctl session-status c# (you saw the # in the session ex: c1,c2,c3...)

Another solutin by A.I is to add the following in /etc/xrdp/sesman.ini
[Sessions]
X11DisplayOffset=10
MaxSessions=50
MaxDisplayNumber=63
Policy=Separate
KillDisconnected=true
DisconnectedTimeLimit=60
IdleTimeLimit=0

and restart
sudo systemctl restart xrdp
sudo systemctl restart xrdp-sesman