The "display in the middle of page" user tour step does not show if the user resets the user tour having scrolled down the page.

When the user is at the top of the page and resets the tour, it displays correctly in the middle of the screen.

Upon investigation I noticed that when you scroll the page and then reset the tour, the "display in the middle of page" step is has a negative top position applied and is outside the visible area of the screen.

Tested this on LMS 4.3.2, and it happens in both Boost and Classic themes.