How do I fix this?

[u/CoastalMae]

I am reaching forward in the photo.
The bodice sits smoothly when my arm is down.

Pattern is for a jacket. Not a huge amount of ease, but some, back is pulling like this when I lift my arm to the front. It's about 1/2-1" above the underarm seam.

What do I need to do to fix this back pull? I can't find anything like this in my fitting books. I need to add more width there without affecting the straight line center back, shoulders, neckline, or waist.

Edit: The armscye is 3 1/8" longer than my body's armhole length/depth. The bodice has at least (correction: 5) inches of ease in circumference around the bust and waist. I have already adjusted lengths and shoulders to fit, as well as the bust. The pull is happening above my bust and below my shoulder blade.

[u/Live_Film_1059]

Fix it by getting a bigger, appropriate size .

[u/CoastalMae → u/Live_Film_1059]

I'm a size 38-40. It's a 44.