Why does it keep switching

[Eternal Wanderer]

I was marathoning the latest Rokujouma volume earlier and at the beginning of the book to turn the page I would have to swipe to the side to change the page I'm on, however at a certain point I instead had to swipe downward to read more. Its by no means a deal breaker but why did it switch in the middle of the book.

[Jaquobus]

Did you maybe accidentally hit the triangle in the menu bar? That one changes the app from
paginated to scrolling and vice versa.