Geometry disappears when I change opacity

Hi,
When I change the opacity, all the geometry vanishes. I think the problem is related to the error message I get when starting Paraview:
Created temporary ‘damBreak.foam’
Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
qt5ct: using qt5ct plugin
qt5ct: D-Bus global menu: no
How can I resolve this? I am desparate!

Should have added: I am running Paraview 5.6 on OpenSUSE 15.4, using the Vmware platform.