Thanks to all for the insight...
It all makes sense now!!!

I use charcoal and some times there will be a few pieces of wood from where I’m cooking ribs and such. That would give me the nitrates and the smoke ring and red color. And... sometimes the coals are going out and the burgers are cooked at a slower rate than they normally do. I also sometimes leave a few burger off to the side to keep them warm as I wait for the other burgers to get done. This is why only some burgers get the excessive red smoke ring... those are the few that are cooking over the slower coals. After sitting in the steam table, they are stacked and blocking off the air. Lack of air and nitrates give you a red, cured smoke ring.
So the solution seems to be to cook fast and hot over pure charcoal.
I REALLY appreciate all of the help. Thanks, Steve