Contact resistance (which should be an order of magnitude lower than a few ohms) would tend to lower the temperature perceived, not raise it. I am suspecting an intermittent open as the more likely eventuality, which would put it out of range on the low temp end -- not that it matters, because the code doesn't tell you which.

Another cleaning? You didn't mention the first one.

--
Art Benstein near Baltimore

Without geometry, life is pointless.