Scroll jump to anchor then back to top

When you have an anchor in the URL that is not visible on load, the page will jump to then anchor and the back to the top of the page.

Start by reproducing the behavior with a URL anchor that is not initially visible on load, using the attached recording as the expected scenario. Trace the page-load and tab initialization entry points responsible for scrolling, then verify that the anchored section remains selected and the page does not jump back to the top.

Written by the indexing model from the issue text.