Auto brightness stopped working

I had replaced the entire front camera assembly recently with a cheap part. I don’t know if that was the reason, but the auto brightness is no more working. The proximity sensor too wasn’t working, but after pulling them out and fitting them back, I got this one working, but the auto brightness is not there to be seen as well as the setting is missing under Display & Text, though a search can still find it.

Should I replace the front camera full cable with a costlier part or is it something simpler?

Help appreciated