New Frigidaire - temperature fluctations

My brand new (had it for about 3 weeks) Frigidaire FFTR1814QW refrigerator/freezer doesn’t seem to be maintaining temperature very well.

Checking it periodically just in the last 24 hours (haven’t made any adjustments
and I’m only opening the door for a brief second) I see a fluctuation in the freezer from -3 to 15 degrees and the refrigerator fluctuates from 30 to 39 degrees.

Is this normal? Food in the freezer and fridge seem fine, I notice beverages vary a bit though, from nice and frosty cool to just acceptably cool.