Hi, new to me 2014 FL2 TD4GS - issue, car will no stay in 6th gear, just pops out. yesterday it did three miles before it popped out but it does it all the time. its going into local, not land rover garage but wanted to ask if any ideas on this from anyone who has experience of this or knows what the issue is? Hoping not needing a reconditioned gearbox.

It could be the cables aren't fully engaging the gear. Or it could be an internal issue with the gear selector mechanism in the gearbox, like a detent spring broken.

The gearbox isn't made by LR, it's a Getrag box, similar to those used by Ford in the Mondeo. Hyundai Ioniq 5 Ultimate. The family car.
2009 Rimini Red SE TD4. Gone.
2006 Tonga Green i6 HSE. Gone.
Audi A5 convertible, my daily driver.
1972 Hillman Avenger GT, the project.