Bingo!!
The temp in the middle of the chamber was at 68.5 and falling when I went to move the temp probe. I moved it to the bottom of the chamber first, and it read 66.4. Then I moved it to the net pot, and it read 74.6!! Id bet those temps at the top could have been even higher when the heater was on full. I have to say, I was not expecting that large a temp differential.
Thank you for the suggestion to check that. I might not have actually done it if not for your comment 