Refrigerator is warm but freezer works fine

Hello,

The model of my fridge is KFIS27CXMS2, it has a refrigerator part at the top and a freezer at the bottom. The freezer works fine, but the refrigerator started to have cooling issues. The refrigerator gets warm and no cold air is flowing from the holes at the top.

I cleaned the back filter/coils and the front one. But it did not solve the issue. If I unplug and wait 5-10 minutes and re-plug the fridge, it solves the issue temporarily for 1-2 days, but then the top part stops cooling again. It's been like this for a couple of weeks now.

Also, water is leaking from the bottom of the freezer (I need to clean the ice buildup from the bottom every week). But this issue has been there for over 4 years. I am not sure if it is related to my recent cooling problem.

Do you think replacing the drain tube will solve both of my problems? Or does the cooling problem require more series repair?

Thank you!