Hello everyone, new to the Forum, hoping someone can please help me out

I purchased a 2018 L200 , which has the same steering wheel controls as the Outlander.

I also purchased a new radio unit

Whenever I try to pair the steering wheel controls, it automatically pairs with Volume Up (even though I'm not pressing any buttons). As a result the volume just goes up and up. One time it also paired with Volume Down.

My mechanic said the steering wheel controls were faulty, so I order a replacement, to no avail - same problem.

Any ideas on how to fix this?

I've added a video, thanks!