I had a similar situation with a Model 29. Bought off a different forum, it did not carry up consistently in DA mode.
I sent it to S&W, $50 overnight, since I'm on the west coast.
After a couple of weeks I called and they let me talk to the guy working on it. Needed a new hammer and hand. The repair was about $100.
All they had in stock was a target hammer, which is nice. But now it no longer fits the safety strap on its Don Hume 721. So, I was out another $50 for a holster that doesn't fit.
Now it carries up on all charge holes. Not really consistently, but it is safe.
Next time, I'd look for a local smith to work with. Anybody could do that work and S&W just did not impress me that much.
Just trying to share experiences. You will get your 19 sorted out and you will love it.