The retension side is correct. The ninety degree angle on the other side, coming down from the horizontal shelf, is not supposed to be there.
I like MI products. This is the first problem I have had. As far as gas block sights, I have never used a railed gas block. I always use FF rails that extend over the gas block. I can see from reading on here that the gas block rails can be a problem. I read a thread on here a couple days ago. And actually it was on MI's industry forum about a guy that could not zero his front sight. What it wound up being was the gas block was not the right height. And I think it gave the different heights for different manufacturers gas blocks.
I think if I was just set on keeping a carbine length handguard, I would just get a one piece gas block with folding sight. That way there would be no question as to what works with what. I'm hoping my new sight shows up today. But with the holidays it may not be here till Saturday or Monday. I will keep you updated on its condition. But you need to contact MI or your distributor for replacement. If nothing else I would post a link to this thread over in MI's industry forum. I'm sure they will take care of you.
Terry
ETA: MI also makes a one piece front sight / gas block. May be able to work something out on one of them.
PRI makes one also. Just looked at on on Bravo Co.'s website. They also have a YHM. There is not many to choose from that I am seeing. Maybe someone else will chime in with more suggestions.