So that's ambient? Why the big drop?
What is the uth set to?
My hoggy was a pain and still refuses frozen. I found mine wanted a uth and a tad higher temp than I was providing. Once things were a bit warmer it started gobbling up live pinks without a problem.
I would recommend getting the ambient to stay around 85 without letting it drop under 80 at any time. Then I would get the uth to 86-90.