PathFollow rotation inconsistent when Path contains control points in XYZ rotation mode

[Flamebeard10339]

similar (not exactly the same) as #13434 and #3713

Godot version:

Godot Engine v3.3.stable.official - https://godotengine.org

OS/device including version:

OpenGL ES 3.0 Renderer: GeForce RTX 2060 with Max-Q Design/PCIe/SSE2

Issue description:

When changing offset (or unit_offset) in PathFollow when the Path.curve has control points it (randomly?) changes the rotation of the PathFollow node.

sometimes the change is marginal. other times it can be as much as +-30 degrees. It also goes in both positive and negative directions.

This issue is completely alleviated when the rotation mode is set to oriented as opposed to XYZ

Steps to reproduce:
create a Spatial.
add a Path child
create 2+ points
add a PathFollow child
grab the offset slider and wiggle it around as wildly as you can.

you should see the translation change, but the rotation stay constant.

go back to the path and shift drag one of the points (add control points)

go back to the PathFollow and jiggle the offset slider.

Transform.rotation_degrees of PathFollow will not return to Vector3()

Minimal reproduction project:

PathFollowBug.zip