Honda EU3000is - Issues with Choke stuck in CLOSED - Spring tension?

Working on a Honda EU3000is for my mother-in-law, and what I'm seeing is that if I pull the Choke knob to the CLOSED position, the choke cable will correctly pull on the choke control and close the choke...
 
If I then start the generator and push the Choke knob in, to the OPEN position, the cable slides through the holder, but the control plate itself remains stuck in the CLOSED position, which obviously makes the generator not run correctly... if I stick my finger in there and nudge the control to the OPEN state, the generator runs beautifully...
 
Attaching pictures so you can see what it looks like when I Pull/Push the knob, as well as what it SHOULD look like when I push the knob (but have to manually set it to currently).
 
I've sprayed some WD40 around all of the moving parts in case it was just stuck, but it doesn't seem to have done much. Not sure if the spring on the throttle cable just doesn't have the push it needs to slide the part back into place, or if there's something I'm missing that's out of view which might be over tightened. Any help & suggestions are appreciated!