The Golan Heights belongs to Israel. Israel was repeatedly attacked by Syria. Syria lost repeatedly. Israel has no desire to give it up and its army is able to defend it B"H. fait accompli. The local opposition to this is almost minimal. Not sure how many of its Druze or Arabs would rather be in Syria nowadays.
Please explain how this conflicts with US interest?
The UN should find another subject to argue about, it's not very interesting. Facts on the ground do matter.