GE Monogram refrigerator freezer not freezing

[krisrak]

I have a GE Monogram refrigerator ZISW42DSB

About 5 days ago I noticed that frozen veggies in freezer was not frozen enough, the freezer was still cold, i check ice in ice maker, it looked like it had started to melt, so I removed all ice and let it sit to see if the ice maker is working, after few hours I notice ice was good and the frozen veggies was frozen. The next morning, i noticed the same that frozen veggies was not frozen, freezer section still cold. I noticed some times of the day it is as expected and other times not as cold.

I watched some videos and check that the defrost timer is functioning (turning). Today I noticed that the freezer section has been same temp, cold, but not enough to freeze and ice is ice maker seemed ok, the temperature at ice maker seem to be ok, just not other parts of freezer, I remove the ice maker and notice from frost on top ceiling of freezer. I also noticed at bottom of freezer where water is collecting, that water had formed thick ice. A technician came and noted that both freezer and refrigerator section are at 45, freezer should be much lower. What could be wrong? next steps to diagnose ?