This pertains to the PDF uploaded to magic.wizards.com/en/rules
The Modern Horizons III (20240607) release had a featured called "Fast Web View" enabled that made it load faster? My browser also displayed a feature called "Document Outline" that made it easier to navigate.
No idea if you have a say in the Document Outline but Fast web view seems like a common courtesy
Sorry that this is the inbox for the Companion app, couldn't find the support page for general MTG game publications