Welcome! I'd remove it to see what's wrong, it's threaded all the way thru so it has to bottom out on the hammer, it should have an 8-32 socket head set screw that will go all the way thru and drop out on the inside of the extension if it doesn't stop against the hammer.

It may be rusted or someone use red loctite on it which will require heat for removal, not to be confused with the red thread locker that comes on them from Uncle Mikes.
Tim