You my friend have the hottest MES out there! What rack levels do you have those temp probes?
The safety rollout limit switch is fairly high up in the back so if you are measuring on the bottom rack on the hottest side (usually right side) of the MES you could get much hotter temps lower in the MES then on the 3rd rack way up where the safety switch is. Just a guess though.
Like bear says I would simply turn down the heat and follow the thermometers. Most people have the exact opposite with an MES. They can never reach the max 275F temp. You have a a super hot MES lol.
