Hello, and thank you for using this service. I'll be helping you with your problem today.So you are correct that the temperature should maintain below 41 degrees and preferably 37-38 degrees. Now that being said, The temperature of the air is not important, only that the food is kept at that temperature. The thermostats are not perfect and I'm not sure how quickly your Taylor thermometer reads, but it might read quicker than the thermistors used inside the refrigerator. Temperatures will fluctuate up and down but there is enough weight to "food" that the temperature should maintain a constant temperature. There is always going to be fluctuation of temperatures of the AIR inside the refrigerator. If you want to make sure the temperature is holding accurately, put a glass of water inside the refrigerator and put a thermometer inside the glass of water. Now the temperature should vary only 1 or 2 degrees up or down from 37 degrees if the refrigerator is working properly. I'd check the temperature the correct way with a glass of water and go from there. If the water is fluctuating from something like 34 degrees up to 42 degrees---there is a problem. You can either return the refrigerator if the dealer will allow you to do so, or you will need to call out warranty and they will come out and check over the refrigerator to see why it's fluctuating so much when it shouldn't.Please remember to rate my service before you leave. If you have any other questions, please ask me – I’ll be happy to respond. You can continue asking follow-up questions until you have all the information you need even after rating my service. Thank you!