Writing region and paper movement

Hi everyone

On my learning journey, I've been closely focusing more on my arm and "static" hand position, for which I've been actively trying to not tilt my hand in an angle, as I've unconsciously and mostly moved my hand to reach the rightest part of the sheet when my arm wasn't able to reach the farthest section on the line, and now I've solely tried to move my arm resting it on its pivotal muscle, without any hand movement, and also avoiding any gliding of that muscle on the writing surface. The more I've been focusing on this, the more limited I've felt,

When my hand is fully static and not tilting at all, and I try to only move my arm, I feel that my writing region has been greately reduced and now I need to move the paper at least 6-7 times instead of 3-4 as suggested by Palmer's book.

I now feel that my arm muscle reaches a physical wall in which I cannot move my muscle anymore and therefore I must move the paper.

On the push-pull drills I cannot go beyond 1.5 cm at most without feeling the need to move the sheet I'm using, and on words' drills even though I'm writing quite small I cannot write more than 2 words (like mine, uses, sell) in a single arm movement.

What could I be doing wrong?
Is this normal?
What are your suggestions around this?