Trees are HIGH, Grass and bushes MEDIUM. Just uninstalled and reinstalled, but same result.
Since the problem is not caused by our scenery, it's normal you won't see any difference by reinstalling it.
but bottom line, without your Addon, KSDF looks fine; with you add on, KSDF looks like this while other airports look fine.
That doesn't mean the problem is *caused* by the airport. If another scenery you installed has done something like reused the guids of standard objects we use and other scenery don't, and replace them with their trees, you would see exactly that: trees ( they should be trees ) on our scenery that will disappear if you remove it, but the problem is the *other* scenery that has done that.
Here's a video I just made to prove the problem doesn't happen, even with different settings ( same as yours, all to Ultra, then back to same as yours )
So, what you should really do, is remove *every* add-on from the Community folder ( just MOVE them out, so it's extremely easy to restore them ) EXCEPT KSDF, and try again.
Then, add each add-on back, one by one, until you'll find the culprit.