I would encourage you log issues against the latest H21 builds so that the appropriate developer is aware of the issues.

I did that and Sidefx told me that Wayland is not supported.
So for now if you get it working on Wayland you are lucky not my case.

qt5 and qt6 works fine on Wayland (Omarchy Hyprland). There are a couple of quirks with missing transparencies and UI behaving slightly different due to the Hyprland's design.
The only issue I have at the moment is flipbooks rendering at much lower resolution and AA levels than the viewport is set to. Flipbook settings do nothing unfortunately.
I will be trying setting up a TOP setup with OpenGL as a workaround and see if that would fix it.

Other than that I am fairly happy with how it runs Cheers to SideFX for providing the 21 QT version so quickly.

qt5 and qt6 works fine on Wayland (Omarchy Hyprland). There are a couple of quirks with missing transparencies and UI behaving slightly different due to the Hyprland's design.

Are you also experiencing the mousewheel zoom/scroll issue on parameter/network view and the status bar at the bottom not displaying ongoing calculations using H21 QT6?

MattiBRND
Are you also experiencing the mousewheel zoom/scroll issue on parameter/network view and the status bar at the bottom not displaying ongoing calculations using H21 QT6?

I am currently using 21.0.440 qt5 with no mouse wheel issues whatsoever (at least to an extent of my houdini usage)
I might be wrong, but qt6 also worked well (that was the version I used before 21 came out with qt5)
Not sure why did SideFX go with the qt5 instead of qt6, they must've had their reasons, but I can't tell much difference except for the glitchy UI (alphas transparencies missing and menus stacking and overlapping on radial menus), screenshot attached.

I think issues are varying by distribution on my case everything regards to UI mouse wheel and transparent menus are working fine but after a while my whole system freezes when I try to access the RMB node info, luckily I can kill Wayland session using ssh but it is not reliable to use Houdini on my case.

By the way I asked Sidefx about plans to support Wayland since every distribution is ditching X11 and they told me they have plans to do that for 21.5.

So I think for now on my case I will have to stick to X11.

@mzigaib omg I had the same thing! Node info with MMB would completely freeze just my screen (music kept playing). I was using Gnome. Now I switched to Hyprland and it works flawlessly. I used to be a fan of Gnome, but after switching I realized just how many of my overall issues were caused by it alone (not just in Houdini).

Interesting, gnome always worked for me so I never though on try anything else but I will check this out.
Thanks for the tip.