Dynamic noise texture scaling issues

I am testing some form of nebula-esque tunnel generated from the noise node.
I wanted to animate the texture along the length so I split off the axis along the length (z-axis) and added a math node to increase the value and then combined it again. This worked as intended.

Then I wanted to test a dynamic scale along the length of the tunnel. I split of the Z-axis again at the beginning and did the math to make the value 14 at the beginning an 28 at the end. This looked fine at first and as intended, but when I want to move the texture along Z with the first system the scale changes as well.

The two node tracks only meet at the Noise Node so should not interact, I thought.
I am new so I cannot share the file apparently
Any help will be highly appreciated!

Here is a link to the file, maybe this works