I concur that it may also be the armhole. Modern armholes tend to be cut fairly deep and wide. Imagine if the sleeves were off the blouse, is the shirt showing your entire bra band? That's a low-cut armhole. It's counterintuitive, but frequently a wide/deep armhole actually restricts motion. Small, high armholes give greater range of motion without having to tug on the rest of the garment. It's actually more fabric, rather than less, that helps. That might be what's happening here. The armholes are too deep or wide, so when you raise you arms, the entire shirt has to pull up as well. Unfortunately it's the fault of poor pattern design/grading and really can't be altered, since the problem is a hole that's already too big. But you can try the "reach the high shelf" test in the future when shopping.
I tried to find some illustrations. The one for #5 at this link shows a too-deep armhole: https://restartyourstyle.com/shirts-fit/ Raising your arms would pull the shirt up, possibly untucking it, and for a woman possibly pulling it up too high above the bust.
At this link, point #5 cites a tight back fit causing the arms to feel tight when moving. I'm not sure this is the primary issue you're having, but it's right that the width - both front and back - as well as the armhole shape and size all need to work together.
https://www.doinaalexei.com/be.....gn-issues-