Low air flow and no AC/Heat in the rear?

Last summer, I noticed that my rear vents were blowing outside temperature air instead of A/C. I tried from the front controls and from the rear controls as well. No AC, just ambient temperature.

This early winter, same deal with the heating. Rear vents are blowing outside air temperature even if I am on Heat. Tried both front and rear controls.

Front vents are working fine as far as temperature control goes. But I am now noticing that even on full front blast with 2 out of the 4 vents closed, I'm getting low air flow through the vents.

This is starting to be an issue as I can't use my rear vents for controlling the temperature in the car and the front vents are low air flow. I'm having a really hard time heating the car when it's mildly cold outside.

I've changed the cabin filter without any change in air flow/rear temperature control. Maybe the rear temperature control and air flow issues are unrelated?