I have been lucky. My FBH has always worked - any problems have been battery related.

Recently, the remote stopped working.
Or so I thought.

By trial and error, I found the FBH remote does work, but only when the car is woken up.
For example, when the car has sat overnight recently and is asleep. Covered in frost.
Remote fob does nothing.
NADA
However, after the remote on button has been pressed…(flashing green) if i THEN press any button on the key fob, such as the lock button, the FBH wakes up.
It works the same the other way round…if i press the lock button and then the FBH remote on button, the FBH springs into life.

I think it is a software problem and i need an ECU somewhere reflashing.

New battery was installed a few months ago.