Okay, I have actually managed to find the answer after all.
In this video from The Epic Singh (https://www.youtube.com/watch?v=PUllpSeR0sw) he covers that disabling Use Pawn Rotation on the Spring Arm makes the head fully stick to the head socket and it’s animations.
This has fixed my problem but now the head-bobbing is very strong.
In this article (Remove Head Bob – FuristicStudio), Furistic Studio (https://www.youtube.com/watch?v=BNxeXHrBNz0) covers how to get rid of head bob. This does work in a way, especially allowing you to moderate how much of the effect you want if you change the Alpha value. HOWEVER, at Alpha: 1 it disables me from moving the camera up and down.
I assume this has something to do with the rotation change you have to do in the node in the anim graph (you need to change the pitch or the character’s head will be sideways).
Lowering the Alpha value makes it so that you keep some of the head bobbing—which is amazing! BUT you lose the ability to move the camera up and down—as I mentioned.
Does anyone know how to mitigate this?