Well, the gas block is the problem. It sounds like it's still not completely where is should be and now it's short stroking but at least it's now sending gas back to the bolt carrier.

The gas block not only needs to be snug up to the shoulder of the barrel but the port in the barrel needs to be aligned to the port in the gas block. That can be a bit tough. Slide the gas block forward and look for the markings where the set screws tightened to the barrel. There should be two sets. Possibly right on top of each other.

Now look at the port on the top of the barrel. Does it look to be clear? If so, the best thing to do is to take a carpenter square or something similar and butt the "L" part of the square against the shoulder while lining the square up with the port in the barrel. Draw a line with something that will be removable after you installed the block like a marker or something that will wipe off with a cleaner. Make sure the mark is long enough to be seen after the gas block is in place.

Next is going to be a bit more difficult. You need to mark the gas block with a line that shows where the port in the gas block sits. You need to do this in order to be able to get the two ports to be properly lined up.

You could remove one of the set screws in the block and try to line up the screw opening with the marks made on the barrel from the set screws but if they are pretty much on top of each other, how are you going to know which mark or where on the marks you need to line up the hole with? The method I mentioned will be more reliable.

Lastly, put some thread locker on the set screws so they don't work loose again. Don't use red. Not unless you plan on using a torch or drilling out the set screws in the future when you decide to do some work or replace the gas block with something else. Blue is generally the best choice. It holds pretty well but will allow you to remove parts later on without too much trouble.