Have you actually examined theeggs to see if they were ineed cooked, or did you look at the temp only and assume they were cooked?

Eggs can stand a temp spike for a short period of time. Seeing a temp reading of 103 does not automatically mean your eggs are finished. It might mean they are on their way to being finished.

I struggle with bator,s but I never assume death of an egg until I have the evidence in my hand, and I never let the temperature alone cause me to toss out a batorful of eggs until I have candled and found them all dead.

Are you secure with your candling abilities? It can be tricky to catch onto, but not impossible. Green or blue eggs are the worst to candle.

But for starts, get a new wafer. And I would NEVER accept the word (temp reading) of any glass type thermometer until I had calibrated it against a medical thermometer. Many, many, many thermoms are WRONG with their readings. Digital thermoms are more accurate as a rule.