[Strange behavior of "scrub"]

@akapowl, thank you, pin is exactly the behavior that was needed! 

[Strange behavior of "scrub"]

I need the following behavior: a container with a height of two screens and an inner container with a height of one screen, when scrolling, the inner container is fixed on top of the screen. I wanted to do this using top: 100vh and scrub, but the behavior is different from what was expected. At 30% of progress, top is 51.222vh, at 60% - 84vh, in other words, it is not equal to progress.

See the Pen bGLwgwV by StartToWeb (@StartToWeb) on CodePen