My coolant temps seem to run on the high side. I have a pretty much stock 2018 JLUR. Climbing long grades not pushing hard or idling my coolant temps and oil temps quickly climb in to the 220's with the outside temps in the low 80's. My radiator fans seem to be working properly and my radiator fins are clean.
I had a problem is similar with a 1982 Toyota 4x4. After trying several things it turned out to be my radiator was plugged internally and having the core cleaned out lowered my coolant temps when climbing grades. I have heard that the Pentastar block is sand cast and that there is a possiblity of residual sand left in the block that can clog the radiator.
What I plan to do is replace the radiator with a new stock radiator. At the same time I plan to add the JT grill mesh inserts because those ones have larger mesh or holes.
I drove a supercharged JK in a ralley in Baja California and had no problems with coolant temps with a stock cooling system.