Unable to change the z angle

@Admiral I think what you are experiencing ks what's called "gimbal lock". By using the gizmo you shouldn't run into this problem. There are ways to account for it with the text boxes but it can be hard to understand.

@pedro16797 Anytime my x angle is at -90 the z angle rotation tool will only change the the y-angle

Have you checked this isn't because of the Global/Local direction?

Correction: the Y-angle changes instead of the Z-angle.