Oh no...This isn't good....you are not the first one on here with a temp drop on their incubator this HAL. I am so sorry this happened to your hatch. Crossing my fingers for you!
Can you try the temps from different locations in your incubator? My stupid Hovabator was running a 5 degree difference in the incubator depending upon location that i put the probe. I never noticed it until i got the Brinsea spot check.So, I don't know whether it was like that since i bought it or i just came across it....
i hope that you can figure this out!
I'm just rolling with it right now (but I had a good cry this morning). I am NOT putting more expensive eggs in there until this is resolved. I even changed my duck egg order that was going to arrive next week to ducklings in March. When this hatch is over (if any hatch) I'm running it for at least 2 weeks with store eggs and see what it does. My only thought is that my cat bumped something, but the controls looked normal.
I'm also looking at my house thermostat, maybe it glitched last night.