Take it back and exchange it for a new one. You could try a new battery - cr 2032 I believe is the number. I do not like the flukers as much as my accurites. And to think the flukers cost around $25, too.
I know they sell the gauges at
petsmart too. You know, the ones that look like a meat thermometer? You can try one of those instead of digital.
I have to wonder though - If you have all the water trays full is your window showing condensation at all?
I had mine at 80% for my last two little chicks because the membranes were so thick and dry. 80% was not with all the water trays full.
I am wonder if you have such high humidty coming up it is off the scale and the digital is getting condensation and shorting out.