Dome temp vs grill grid temp

Hi everyone. I just picked up a used Joe Jr. yesterday and cooking on it for the first time today. So something I've noticed with my BGE is the difference between the dome temp reading and the grill temp. It's never really been an issue because after the ceramic is thoroughly heat soaked on the BGE, the temps between the two more or less even out. But now with this Joe Jr, once I put the meat on, there's almost a 100 degree difference between the two. I'm sure it's probably just a learning curve thing as I've never cooked on a grill this small before. But I was wondering how you all track your temp. From the dome or grill or both. Or am I just doing something wrong. Thank you.