I have a GE Profile fridge GFE26GMKHES. Early in 2023 food was freezing in the bottom drawer of the Fresh Food (FF) compartment. Your problem is in the FreeZer (FZ) compartment, so not the same as mine, but maybe the following will give you some more ideas.
The short version of the story is that I replaced the main board which fixed the problem. I decided on that course of action after much head scratching and experimenting. One morning I noticed that a fan or motor was running constantly, which seemed odd given that the fridge had been closed all night. It took some time and careful listening to distinguish among the various noises, but I finally concluded it was the compressor motor. As far as I could tell, the thermistors were not the problem, so I decided that the fault must be in the relay on the main board that controls the compressor. I never tested the relay to prove that's what was wrong, but the problem did go away when I replaced the main board,
One more thing regarding how to measure the temperatures in the FF and FZ compartments: I used a couple wireless recording thermometers. See the Amazon link below for the ones I used. They are pretty cheap and they work without opening the fridge. They provide a log of temperature over time as well as a comparison to the self-reported temperatures you get from the fridge itself. Here's the link: Govee Bluetooth Thermometer 2-Pack.