Should the trailer stability assist icon be permanently lit when a trailer is attached or only when indicating on a 2015 RRS autobiography dynamic

Also when a trailer is attached should the parking rear sensors switch off

I am using LR dedicated writing harness 2015 RRS Autobiography Dynamic Corris Grey Black Roof

If you're retro fitting the towing system, it will need to be "activated" in software too so that vehicle recognises it and performs correctly. The parking sensors should turn off when a trailer is connected to the electrical plug. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

The tow bar was a retro fit but it’s LR designated electrics its showing the trailer icon but only when I indicate and I wasn’t sure if it should be on all the time when the engine is running, should they be or not?

The rear parking sensors beep when I put it into reverse so I will need to speak to the company who fitted it for me 2015 RRS Autobiography Dynamic Corris Grey Black Roof

The lamp just means the trailers indicators are functioning I expect.
A legal requirement in uk