Mk3.5 focus rear camera led issue

[Brammer_2k]

Hi all, I've tried to search for this but cannot find anything. 

Issue is this, when I have all lights on and I go to put something in the boot the number plate lights are off, some times there working fine, sometimes there not and sometimes come on when I close the boot. 

Issue I have is that I have the rear camera where the number plate lights go and from reading the Haynes manual you have to change the whole unit if the lights fail and with it having a camera in it I know its going to cost a lot. 

 

So if I can replace the bulbs in this that be great. 

Unless anyone else knows why my car does this? 

It's a 2015 1.5 tdci titanium so out of warranty and the camera is the one you can get as an option from new. 

 

Thanks