You can try different thermistor lookup tables or create your own if you've got a reliable temperature probe, ie a thermocouple with an accuracy of around 2 degrees c.
But if the reading is fixed at that value, even though you hold the thermister in your hand you may have a wtong value or broken thermistor. It could point to a broken arc input port. Swapping pins may help.
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Kind regards
Imqqmi
NFAN CoreXY printer:
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