Painting - Rough finish on smooth ceiling

I have a new drywall ceiling that is about 400 square feet and in 3 sections. I had a professioanl painter come in and paint (I hate painting). 2 of the sections look fine. the third looks terrible. We looking at it from an angle, it looks like it is partially painted. Upon inspection, there are big texture differences in parts of the ceiling. Some parts are smooth, others look like he painted a sponge. I want a smooth ceiling- no texture. I put 2 coats of paint on it and it helped a little. What should I do next?

I think the painter must have put on a second coat before the first was dry. I know that I don't want him back..

Sanding may not leave everything with the same refractive surface, a stripper may be in order, but the right one doesn't come to mind right now, maybe another pro can help out here. Seems I've seen a product for stripping texture, don't know if it would work on paint.

I would try sanding with a pole sander and drywall paper first, if it doesn't want to work out evenly, you may want to consider skim coating the ceiling with topping/texture compound, then prime and paint.

My best

Sonnie