Since the update to Calibre 8.1.1 and sending sideloads automatically as kpubs,
, I've started to see my News downloads, both CBC and Al Jazeera for sure trigger the reading menu as a pop up when I chose an article in the chapter section. I think The Economist as well.
Choosing the link takes me to the article as expected, but the reading menu is opened. That's the menu that would use to start the change font process or go back to your books listing.
It's an older Kobo, the original Aura. 12 years old, no more support/firmware updates, but still going strong.
It just takes a touch on the screen to dismiss the menu, not a big issue by any means. I wondered if anyone else has noticed this happening. I've never seen this behavior before.