For anyone that might be interested, I’ve finally got my headlight range control issue fixed. After wasting money on auto electricians who hadn’t a clue, I eventually took to it the main dealer. 4.5 hours later they discovered that a wiring loom connected to the range control module was not fixed in place properly and had been rubbing against the steering shaft. Over probably a few years this has gradually worn through a wire and caused a short circuit.
It’s cost me a lot of money to get it sorted, sadly most of that wasted on so called professionals, but just happy it’s finally sorted.