I've had some character morphs that require you to inject the head and body morphs before injecting the morphs from the character package.

Try injecting the head morphs for M3 before injecting the ones for the character addon and see if that helps.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi