I hope somebody can respond to this situation, because I have had the same experience. Took it to a smith and it worked fine for a while, but the problem came back. I have found that if you don't lock the tube follower in place, it will not jam. Of course it must be held muzzle end up to get it to feed. Regardless, not a pleasing situation. As an aside, mine has done this regardless of cleanliness.
So, I second the call for expertise on this topic!
So, I second the call for expertise on this topic!