Update, definitely a tv tuner issue as well as something else.

Plugging the Nav directly in to tuner location as suggested in another post does nothing even with a known working NAV. Putting in a known working tuner also did not resolve the issue for me so there has to be another component in the loop causing this problem, I have checked all wiring and plugs and all is good there.

I can also confirm in my case, the Navigation does not run the display, the tv tuner does once the white plug is connected. This is the case in both my facelift X5s.

Very puzzling 🤔