New Scratch and Dent Whirlpool Side By Side (wsf26c3exf)

Freezer temps are all over the map since first installing it 2 weeks ago. The temps are set using the front panel. The freezer is set to 0°F. I've seen it as low as 5°F and high as 25°F, but mostly above 20°F. Fridge is set to 37°F, and maintains 37-38 degrees pretty consistently no matter what the freezer is doing. I am having zero luck with my repair service technician, so I'm trying to gather my own intel as to what will fix the issue. I've narrowed it down to:

1. door seals (brand new fridge, so highly unlikely)
2. freon (it's possible this unit sat around a while, but it blows very cold air)
3. air flow (I checked for blockage, it all looks and feels right)
4. defrost timer

I'm leaning towards a defrost timer issue. The 1st sign things were not working properly is that ice wasn't being made after 3 days from 1st plugging it in. Water dispensed correctly. Repair tech came out. Fridge diagnostics reported that freezer wasn't cold enough to make ice. His solution? Replace ice maker (wrong). While waiting a week for the part the fridge started making ice on its own. There are times when the freezer gets somewhat cold (below 10°F) but it mostly stays too warm. Tech decided not to replace ice maker. This weekend several items in my freezer started to defrost. I pulled out a frozen pizza to cook and it was pretty much defrosted. Checked the temp this morning and it read 20°F. I'm not in and out of the fridge much and I live alone. It should easily be able to reach 0°F considering my usage.

Any suggestions will be appreciated. I may call Whirlpool directly and see if I can pick a different repair tech that knows what he is doing.

Remove the freezer panel and wet your finger. Stick it on the exposed evaporator coils at the top, sides and bottom. If it fails to stick at most places, you have refrigeration problems, probably not a clogged capillary. Also, check for operation of the condensing fan in the back.