Sorry about the delay. No, as far as we can tell the issue is just the IP catalog. I've run into issues like this in the past where something is trying to pop open a window and can't and things hang.
In this case we ssh into the machine from a x-term and use x-window forwarding (X11 forwarding) to forward the gui to the machine running a program called Fastx, similar to VNC. We do not VNC into the machine in question because modern desktops use too many resources. I can run a desktop from the console so will try that.
As for the machine, it is a brand new Dell server with 256G of RAM and two high-end multi-core Xeon processors. It is plenty big enough. I'll try logging into the console to get the desktop (gnome3 in this case) to see if I see the same.
The interesting thing is that the other machine running three sessions of Fastx and a XFCE desktop does not have this issue. We normally do everything else, like simulation, on this machine to avoid the resource problem with modern desktops running under VNC like programs. The IP catalog opens fine. This is what makes me think there is some issue between QT, the Quartus GUI, and not x-window forwarding under Redhat 8.4.
I'm updating another machine to ubuntu 22.04 and will try the same with XFCE, Quartus, and x-window forwarding. The only reason we run RHEL 8 is because our simulator, Questa, has issues with the versions gcc and certain uses of C++, system C and system verilog in our simulations. We generally are using the biggest parts (S10 Agilex) and stuffing them full so we have some pretty complex logic.