I thought this was worth a post as I have seen this come up since the patch dropped. As you know, the Diablo 4 unique stats have changed so why are you not seeing the changes on your unique?
The simple answer is the stat changes are not retroactive which means to get any new affix stats on your unique you are going to have to find them again. Yes, you will have to hunt down the new ones to get the new full stat changes.
While this sounds like a hassle, it does make sense as the aspect on the unique will change but the old version of the item’s stats will not change. In other words, when they updated the uniques in the patch, there’s an improvement to existing items and a full improvement to newly acquired items.