Why is my freezer and fridge temp often over the norm for long period

Hi, I just got a new Whirlpool refrigerator (Model # WRT318FZDW) from a well known housing chain and temp. was fluctuating too much. Sometimes the fridge temp was under 30 but other times it was over 40 F. The freezer would go to minus 2 but then to 8 degrees F. This was on recommended settings. On high setting it would go close to -10 but then creep up. Unplugging to reset didn’t solve anything long term. It seems that it would only put on the compressor once in a while, so I brought another one.

NEW one , same model came yesterday, worked great at 1st but then same thing. It fluctuates low and high all day, even with door closed. I just checked and freezer was 12 F and fridge 42, too warm.

Not sure what to do. Have a tech(its in warranty) come check, or have store swap it out for my THIRD one.

Review site has good score, but I don’t consistently get temperature that is in the review.

https://www.reviewed.com/refrigerators/c....

Any ideas? I have 2 fridge thermometers in fridge and one in freezer. 2 inch clearance in back, and tilted back to make sure doors keep close. Gaskets seem good.