Hello,
if you are using XFCE, then please disable compositing: /usr/bin/xfconf-query -c xfwm4 -p /general/use_compositing -s false
Best Regards, Juri Grabowski
P.S.: https://wiki.x2go.org/doku.php/doc:de-compat https://gitlab.xfce.org/xfce/xfwm4/-/issues/551 https://gitlab.xfce.org/xfce/xfwm4/-/merge_requests/134