Built-in KitechenAid refrigerator - freezer temperature question

Question

I have a KitchenAid refrigerator (ksss42qdx05). A few weeks ago, I noticed that the temperature in the freezer got higher than before. I purchased a wireless temperature sensor and logged the temperature. I see that the freezer has a defrost cycle every 10 hours, and the temperature increased from 0~6 degrees to 15-20 degrees. After the defrost cycle ended, the temperature drops somewhat fast to 10 degrees and then took another 6-8 hours to come down to where it was. When the temperature reached at the lowest of the cycle, it was almost time for another defrost. Would you please let me know if this is considered normal? If so, what could be wrong? Thanks in advance.

EDIT: I have already opened the panel and examined the evaporator coil. There was no ice blocking the air inlet nor no built-up ice on the evaporator coil.

The temperature graph can be found here at https://www.dropbox.com/s/ub0w6r5ikxo2raj/Screenshot_20210725-110352_Govee%20Home.jpg

Answer 1

This is not uncommon in the case where the bottom drain was blocked and frozen over.

In the case of ice blocking the air circulation I would remove the lowest shelf and look for ice on the bottom.

I have personally had this happen and saved friends a service call on freezers just out of warranty.

Check it out. It only takes a few minutes and if there is ice blocking or partially blocking the bottom air vents in the back that circulate the air, cleaning that ice out will have it back to normal.