Did you check to see if you have water in your incubator? That would only make sense: if you're getting the same reading everywhere, you must not be getting moisture in the incubator. Do your pans have a leak? Is this your first time with this set-up?
I have the same one as jm93030 ... cheap, simple to use, small, and I love it.
Check your water trays. Don't worry about your thing being wrong anymore, but start troubleshooting your incubator. If you're getting the same reading everywhere, it might just be right.
Good luck .. I hope it's not too late!