Redhat just updated to RHEL9, which defaults to wayland now. 

Literally every mainline distro uses wayland by default now, and SC is imcompatible with it

Yeah it should say legacy linux support. You can edit /etc/gdm3/custom.conf and uncomment WaylandEnable=false to force the machine to use xorg only, but this is a workaround. Screenconnect is broken out of the box for modern linux. 

The technical reason it is broken is because Wayland does not allow root access to the display server, for security reasons. ConnectWise will have to be updated to use polkit and pam, to gain the necessary privileges to the display server instead of just running as root and assuming access to everything like it worked in xorg for the last 25 years.

They did this for Macs already. The display server restricts access until you enable it to escalate properly in the system menu.

It’s just a matter of ConnectWise updating the software to follow the proper escalation channels instead of rooting at everything . And they appear to have no intentions of doing that

this is still not working 5 years later.

wayland is the industry standard now, rhel is the only one not shipping it default now because rhel runs 3-5 years behind. Connectwise is broken out of the box on most linux distros