I noticed the freezer (bottom mounted) not freezing as good as it used to a few weeks ago. Ice cream stored on top drawer would be very soft. I can see about a 4 inch diameter patch at top of back right vertical wall with frost on it, looks like frost from air (Rime ice?).

I cleaned under the fridge and all the vents I could get to, they were all covered in dust/hair. I could see the fan at the back of the fridge running which I believe dries out water on bottom of fridge. The cleaning did not make any difference. I checked the door seal and all seems to be working well, even cleaned them all off. There does not seem to be any overfilling of the drain as I do not see water/ice coming out of the back wall but I have not removed the back wall panel to check what is going on. I also have not taken off the back panel of the fridge over the fan to see if properly draining or not.

Any suggestions?

Thanks