Posted it in discord. CONTACT_KEEP doesn't trigger.

Hm..
Perhaps It's not supported for the PhysX version being used:
https://github.com/Esenthel/EsenthelEngi...ing.h#L109
\note Triggers do not support this event. Persistent trigger contacts need to be tracked separately by observing eNOTIFY_TOUCH_FOUND/eNOTIFY_TOUCH_LOST events.