air blowing like bi-level in heat mode

I've read some previous forums about this problem, and I've looked into the solutions, but it still isn't working.

I found 3 "actuators" (I believe they are called) under the dash area and have looked to see if they are all working correctly as I turn the dial. They all appear to work just fine.

I checked the vacuum on the black hose connected to the purple and it seems to have plenty of suction.

So now what?

Is there another actuator that I haven't found that could be faulty?