Sorry you are having these issues.
Sometimes you just get a lemon and need to dump it. There have been many reports of perfect Shields in all calibers from day one and onward. Problem firearms are frustrating and can be expensive running ammo through it making sure it's reliable and shipping it back and forth to the manufacture. Not often, but over the decades, I got a lemon, but cut my loses and moved on.
Hopefully it all works out for you.