Freezer cold but fridge is warm even after replacing evaporator fan.

Everything was working fine until one day I noticed the fridge was warm and there was ice buildup in the fridge. I took it apart and noticed that the damper was completely closed. I ordered a new damper but in the meantime I removed the back panel of the fridge so that the vent coming directly from the freezer is unobstructed (the damper is still connected so it doesn't throw error codes).

However, even after doing that, the fridge is still warm. The freezer is still at a consistent 0 degrees and now without ice buildup. I checked the evaporator fan and it was still running but I replaced in anyways. If I put my hand directly over the vent from the freezer where the fan is, I can feel some air moving but not enough to cool down the fridge. I also took apart the freezer and the evaporator coils look fine (light even frost without ice buildup) and the drain isn't blocked. I'm completely stumped and don't know what else to check before calling someone out.

The fridge is an LG LFXS26596S