Okay so I tried again with a completely new project file in Ch and it worked completely fine.
Im not sure where the problematic preference lay because it was affecting all of my characters not just the one.
All of their mouths would scale instead of have the y-position move with the Nutcracker Jaw behaviour. Very bizarre.
So if you're having the same persistent problem scratch your Ch project file and open a new one. It worked for me.
And for the adobe testers I can supply the dud project file if you require it.
"And for the adobe testers I can supply the dud project file if you require it."
Please do. I can take a look and if it's a bug, I can file it and we can fix it.
Yes, if you could do File > Copy Media Files into Project, and then .zip up the whole project folder and send me a dropbox link or equivalent, we'll try to figure out what went wrong. Thanks!
(You can Undo if you want the project to go back to referencing the source artwork in the original locations.)
wetransfer link supplied above.
Thanks for the link. Cute character!
The problem was that you had set the Face behavior Mouth Strength up to 100% (it defaults to zero, so when you started again, you didn't have that problem). The Mouth Strength determines how the scale & position of your mouth maps to the scale & position of your character's mouth. We default it to zero because it tends to look bad when doing mouth-replacement animation, or nutcracker-jaw style. It can be useful if you're doing neither of those.
I also noticed that the stem is fixed in place in the middle, and thus no lower "torso" movement happens. To fix that, create an "Origin" guide layer in PS near the bottom of the stem (though not right on top of "body bottom fixed", just in case one clobbers the other). I think that's a bug, where the default center origin acts like a "Fixed" handle.
Awesome! Helpful advice and thanks for the Origin tip, I'd been trying to figure exactly that out and ended up giving up on it.