Apparently,the table was not machined flat, or the boss in the housing upon which the table pivots is off. Maybe split the difference? 89.8* on either side? .2* is very small across the depth of cut for the saw.
Casey

Casey - thank you. I'll check the table of the saw for flatness with my level and I will most likely split the difference. I just don't like spending the money on something that isn't right. Oh well. I'll take your advice and see how I get on. Thank you for the recommendation.

I have that same miter saw. I gave up trying to do crown molding miters with that saw long ago. And I have a Freud Ultra Fine (80 tooth) blade plus another cross cut blade along with the stock blade.

My problem was stepped cuts when doing other than 45 degree miters. The stock would move ever so slightly mid cut---creating a gap in the miter. Even only one half would cause the gap. I did a lot of testing---using hold downs/clamps and still had the problem.

What I do instead is cope cut inside corners and use a portable table saw(Porter Cable job site model) and home made adjustable sled/Incra V27 miter gauge for the outside corners.

Coping inside corners takes a bit of time and a couple different files, but it is faster than making three bad cuts. And coped cuts are not affected by humidity/moisture.

I do picture frames miters on my wood shop saw with a sled or the V27 Incra miter gauge.

The DeWalt(had to have the arbor bearings replaces from excess use) is relegated to fencing/decking/etc. It works just great for those jobs.

I don't mind coping. I did fine the fence wasn't straight so I fixed that this morning. I will work on trying to square everything up the evening. If that doesnt work then my father in law is giving me his radial arm saw and I may use that for 'precise' miter work. I would have thought ~$300 would have buy you a quality product. Oh well...

$300 does buy a quality product. But not for making fine fitting miters.

The RAS may well be worse---long arm allows opportunity for a lot of slop.

Saw only gets you so far, that's why there are miter planing jigs, and those Lion Miter Trimmers that use a huge razor knife.
Miters are totally unstable "joints" anyway; the angle and fit changes as the wood shrinks or swells; generally useless for widths over 3".
Casey