I just came across this in my quarters, its a 2019D. I have just purchased a microscope, and was playing around with it. I haven’t ever had the opportunity to look this close well roll hunting.
Welcome well to me it looks like you hit the jackpot looks like D/D to me not M/D the letters are side by side not one on top of the other.
I have found DD before. But it has always been visible by eye. I actually have a 1966 half dollar with the same effect on "in God". That one isn't as prominent as this.