Pcars 2 weird flickering in right panel

With the new Pitool and the workaround from Park How to play project cars on pimax 8k, 5k without parallel projections and steamvr I was finally able to play Pcars2 with a Pimak 5k+ and my puny GTX1070 graphics card.
All was well for a few races, but now I got this weird flickering on the right panel.
It’s as if it stops tracking for a split second.
It’s only the right side panel, and it only happens in Pcars2.
I tried changing every single setting, but it won’t go away. Nothing has been updated or changed, so my feeling is that it might be some hidden setting that has changed.
Is there any way to totally reset the Pimax settings? Or does anybody have any other suggestion on how to fix this?