Hi @codeling
Indeed, many changes occured on the OpenVR module with the generalisation of many features.
The new code is tested, both by test in VTK itself and by the ParaView XRInterface plugin (and many other application using it).
So first I’d suggest trying the test on your setup to make sure they work,
then you could try to bisect the issue on your side, or take a look into the tests to understand how they differ from your app.
Maybe @Thomas_Galland or @Tiffany_Chhim have more insight