This is another new one, doesn’t do it on start up or any general journey, but there’s one bridge I cross and this pops up every time I’m in a certain direction ruin on the, or approaching the bridge, totally weird.

Windscreen is also clean.

Ignore ‘ruin’, don’t know what autocorrect was thinking….

I had this last week when the auto high beam also stopped working, I cleaned the area of the windscreen where the camera is and on restarting the next morning both were working correctly again.

If it's just in one specific location, sounds like there's some particular geometry of the signs on that bridge that causes the car to think the windscreen is dirty.
It might be worth taking the camera off and cleaning the inside of the windscreen of any streaks or grime that might not be visible from the outside.

The Windscreen wipers can only work so far...if you are driving on filty roads and there is a lot of crud thrown up onto the windscreen, the car will complain and temporarily disable your High Beam Assist/Traffic Sign Assist and any other functions that the camera is used for. Better windscreen wiper blades (switch on ignition, switch off ignition, and press down on the windscreen wiper control for 2 seconds....will put the blades into service mode. Wipe them down with a clean microfibre cloth. Ideally replace blades every year. Use a more concentrated blend of screenwash too.