What is your front sight mounted on?
If the gas block is a bolt on version, it can be loosened and shifted slightly clockwise or counterclockwise (to the left is what YOU need) as needed to correct the mechanical windage offset now present. Otherwise, reindexing the barrel may be required.
If the front sight is attached to a free floating handguard rail, it might need shifted slightly to achieve what I described with the bolt-on gas blocks. I'll bet a really "clever fellow" would make up his mind which rail slots the YHM bolts to, and DREMEL away enough material on one side to move the front sight over to one side. Again, you want to physically move the Front sight to the Left, if your Rear sight is too far Right at present. HTH.
You can also check to see if the flat-top rail surface and front sight/gas block mounting rail surface are in the same plane by laying sections of cleaning rods across each area, and looking at how they line up when viewed from one end.
Paladin