Problem with my polo - Weirdest one

[Hssan]

Hi everyone.

I own a polo Mk4, and I am having the weirdest problem with it, I really would appreciate it if you help me fix that.
For the record, 4 mechanic men and 3 checks didn't manage to find what's causing that issue.

The problem is the following: The car will stop whenever you change gears (1st or 2nd) and don't press the gas pedal, or simply when you put it as neutral and don't press gas pedal, it will stop.

Before it stops, the car would start struggling a little, if you don't press gas pedal, it stops.

Note that this only happens between the first gears, it doesn't happen when I'm speeding in a normal road.

And it starts struggling so hard whenever I turn the lights on, which might lead to an engine shutdown, it's the same thing as changing gears from 1st to 2nd or reverse.

Note that I've changed the following pieces:
3 ignition coils
3 spark plugs
throttle body
gas pump within the last 3 months
fuel filter within the last 3 months
Changed the battery

Is there anything else I should do with it?

Thank you!