2015 GMC Canyon heat issue

Hey everyone!
First time here, I apologize in advance if this is not the correct area (please let me know)
I have been battling a heat issue on my 2015 GMC canyon past few months.

Initially it was the heater core that went out, had that replaced by the dealership.
Over the course of about 3 weeks, my heat got weaker and weaker going more cooling than anything. I do not live in a colder area during spring (East TN) but some mornings it is nice to have.

With that, I believe I narrowed the issue down to the heat actuator. I am unable to turn it by hand (admittedly not sure if I am suppose to). However, I took it apart and cleaned all the gears and put the recommended GMC grease back in that I found on another forum, this allowed it to spin freely again while on power from the truck.
Turning the controls, it worked perfectly.

I installed it back into the truck and when I tested, it was a warmer day, but it felt hotter than outside.
This morning, I get nothing but cold air.
Put my hand on the actuator and I do not feel or hear anything moving.

So after that long chain….could it still be the heat actuator or is there another area that someone can point me to and investigate?
I did also recheck the heater core, both in and outlets for the heater core are hot HOT to the touch so that tells me it is circulating.
I checked the climate control modules, everything on there works, even AC and volt meter says I am good in places I checked.