Hash doesn't add "is-selected" to the slide + more...

It also doesn't update any of the slider state, so the first slide still contains "is-selected" class, and the left arrow is greyed out, even if the hash/Id is the last slide. I can _see_ the slide, but I have to click the right arrow as many times as there are slides for it to work with the full screen module.

Any thoughts?

Reproduce selecting a non-first slide through its hash/Id while the full screen module is active, then inspect how hash selection updates the slider state. Done means the targeted slide has the is-selected class, the navigation arrows reflect that slide, and the full screen module works without repeated arrow clicks.

Written by the indexing model from the issue text.