No connected network drive on this machine.
But I cross-checked with my notebook. There is a disconnected network drive but WaveLab runs smoothly on the notebook.
Update:
GUI issue is not noticeable in Frequency EQ or Voxengo Curve EQ, but e.g. in StudioEQ, MasterRig or Compressor
Some Logitech applications seemed to cause the issue.
I’m using Logitech mouse and keyboards (both wireless), also a Kensington SlimBlade.
After deinstalling the Logitech applications the GUI-behaviour got better. Not sure if this solved the issue completely.
Will continue watching it.