regardless of what any laws or guidance might say, this is reality
I've lived worked and played in shitty areas, and now I'm lucky enough to live in a slightly nicer area.
It is patently obvious that you are treated differently in these different places. There is a police logic they use, find you in a shitty area, you must be trouble. Find you in a nice area, you're probably an intelligent middle class employed person and good day to you sir.
I can't be persuaded otherwise, I've encountered both sides time and time again. I used to live in an area where I was basically harassed by the police for living there. I now live somewhere that once a year the police knock the door to introduce themselves, give their mobile number in case I want to report or ask anything, and they investigate someone nicking the badge off my car. So I've gone from 'guilty' but they just haven't worked out what I did yet, to innocent and offered counselling by victim support for a stolen badge. The only difference was my postcode.
Right or wrong, that's reality.