Start over with another drywall contractor? Who hung the drywall? Is the ceiling joist flat?

Change your framing or change your expectations. Weren't engineered joists used?

As much as I do not like it, consider putting a texture on the ceiling.

The brighter the light bulbs you put in the recessed fixtures the less likely anybody will notice the ceiling.

The joists were engineered. The crew came back a few times to feather seams. This has led to substantial texture differences since the whole ceiling was never skimmed. You can easily see where the mudded areas are as opposed to the plain drywall. How would we go about blending the newly mudded areas with the previously rolled ones?

Find someone in your area that specializes in ceiling repair. They can probably skim coat and level out the whole ceiling.

I'm just listening in, because we have the same problem on walls and ceilings in our new build. The contractor never got the mudding/sanding right before painting, and it shows.

Beyond what has been said. Just kinda spitballing here but have you checked the moisture levels. And what types of primer n paint were used. And what price did you pay. And expect a cieling with no texture ? That's a lot of extra work and materials. And I suspect most drywall finishers would not bit a job with flat finish lid. Or it would be expensive

Kinda asking if you maybe got what you paid for. And moisture can effect the finish

We have no texture, flat ceilings and walls throughout the house we built in 2021. That was one of my specifications for the build, smooth walls and ceilings.

My builder hired the subs that could get the results we wanted ... and we paid what they asked. This is in FL, which tends to have more textured ceilings/walls compared to homes in the northeast.

I would hire a new drywall company and get good references. Flat ceilings and walls are normal in a lot of areas. I much prefer them to textured ceilings.

Did your drywaller specify the level of finish they would provide?

A perfectly flat ceiling will cast no shadows from the lights and a hard task to achieve by most drywall finishers. You'll need a skilled perfectionist to accomplish this task who knows how to use a 3' and even a 4' skimming blade along with a good light to make it perfect.

In most cases not all floor trusses or joists in a plane will not be level with a variance large enough to create waves and therefore will cast shadows even beyond the taped seams. So for the ceiling you desire finding these variations by a trained eye holding a light and marked is the first step. These highs and lows must be filled and blended and time consuming to say the least so be prepared to pay a premium for a truly qualified perfectionist and the time required to make it happen.

Perfect is what I have in all my ceilings I transformed from the dark dreary textured ceilings to bright clean spectacular ceiling I have now. Textured ceilings are OK if you like feeling like you're living in a cave. If your ceiling was done right the light would flow deeper into the room and brighter.

Put curtains or blinds on those high windows.

You will never get what you want without paying double for a full Level 5. That's a BIG upgrade to the Level 4 that you have. You aren't even supposed to view the ceiling with glancing light across the surface. That will show shadows every time. Even on a true Level 5. Unless you want to pay ridiculous labor rates well above a standard level 5 skim coat. Because the drywall would need to get redone, and maybe some of the joists, if they are out of plane.

"Residential Construction Performance Guidelines for Professional Builders and Remodelers," published by the National Association of Home Builders is a well-known and widely applied quality standard. Here's what the Guidelines say with regard to drywall joints protruding from the surface:

"Any joints that are readily visible from a standing position facing the surface at a distance of six feet under normal lighting conditions are considered excessive." I would expect a level 4 finish to meet that performance standard and would expect a contractor to repair joints which don't meet the standard.

If I compare what I think are shadow lines with the door width, I have no idea what's going on.

Hopefully sheets run perpendicular to framing, butt joints staggered, and used 5/8" if framing spacing is 19.2" or 24".