Hello all. Just installed a couple of Brinkman Grill thermos at grate level on my New Brinkmann Trailmaster Limited edition. I did the boiling water test to the thermos and they were spot on but once installed, they are not giving accurate readings versus my digital thermos in similar positions. Any idea why? FWIW, these thermos only have about a 2 inch long probe vs what I've seen most have which is a 4 inch long probe. Could that be the issue and if so, why would it be an issue? It's a really serious discrepency I'm seeing in the neighborhood of 30 -50 degrees. Thanks!