I have a beverage cooler fridge with auto defrosting. Twice a day, the fridge would go on defrost mode and the internal air temp would rise from 36 to 43 (as high as 45), more specifically and importantly the temp is above 40 for about an hour. I also have a second (inkbird) thermometer thats dipped in a bottle of water. The inkbird thermometer shows that the water temperature holds the temperature better and only stays above 40 degree for only about 20 to 30 minutes (and only increased to as high as 41).

is the duration of above 40 degree concerning ? and is the auto defrosting mode based on a timer (every 12 hours) or is there a sensor that detects when frost is built up and defrosting is necessary.