Temp never changes

I just purchased my first H&T and I am not sure if I have configured something wrong, but the first night the temp was recorded changing from 20 to 18 over night, but since then it has been 19.5 all day and all night. I put it outside at 5 and still no change after 15 minutes of waiting.

nevermind it seems to have started working again, not sure why the long stall all day. Regardless even at a threshold of .5 it does not seem to respond quickly to changes in temperature, I like the form factor but I don't think this will work as a home low temp alert

I saw the behavior when switching from the power adaptor to the battery. But it as been working seemingly okay for a day, so maybe I was just too impatient