Soldato
Right, it turns out that it was an EMI issue. Well, mostly.
I tested without VR and had the same problems.
Moving the nobsound amp USB a few slots down on the hub caused it. It was the only thing I hadn't switched off when troubleshooting and that small change somehow messed with everything and caused problems even with everything else turned off.
Sorted now, although I do have noticeably lower FPS than before and openXR in ACC is still single digits since the Meta update.
I tested without VR and had the same problems.
Moving the nobsound amp USB a few slots down on the hub caused it. It was the only thing I hadn't switched off when troubleshooting and that small change somehow messed with everything and caused problems even with everything else turned off.
Sorted now, although I do have noticeably lower FPS than before and openXR in ACC is still single digits since the Meta update.