Set to 46° but found my water at nearly 31° and the inkbird reading at 50°

I use my ITC-308 waterproof inkbird to regulate the compressor on my freezer to function as a cold plunge. After a recent water change my control was set at 46°, but this morning I found my water to be slush and measured at 31° with an alternate thermometer. The inkbird was reading the water temp at 50° and was set in the cooling function. Help! I have it unplugged and waiting for the ice to thaw to free my probe end off the side wall of the freezer.

Please check whether the ITC-308 probe is intact?
Please clean the probe and cable, then use a hairdryer to dry the entire unit for a while, then test the probe in the air temperature, can it read correctly?
If it still has problems, please provide the link to this post and the order information to email for after-sales service.