Ah, thanks and sorry for the misunderstanding. Yes, that might be the way to go now. We were now jumping between combinations of VTK 9.2.2 & VTK 8.2.0 + Qt 5.12.6 & Qt 5.15.7 (suspecting that Qt might have had some influence) and given the outcomes, we will probably have to bisect the VTK more properly.