It was restricted by «Autoplay Policy Changes»: https://developers.google.com/web/updates/2017/09/autoplay-policy-changes#iframe

new API methods for getting horizontal/vertical slides, force linear navigation for one-dimensional decks

iframe background preload behavior now matches inline iframes + adheres to the new 'preloadIframes' config option

Allows lazy-loaded (i.e. data-src) iframes to be preloaded when they
come within the viewDistance, rather than once they're visible.

Scenario:

- history set to false in Reveal’s config
- follow anchor to `/#someid`
- navigate to other sections
- follow anchor to same section `/#someid`

This does not work as the hash has not changed.

This fix removes the hash from the URL when navigating