Jukey wrote...
the "2 pages when possible" mode broke for the vast majority of magazine chapters a bit over a month ago from what I can tell.
magazine chapters start with page 1 by itself on the left, before becoming two page spreads until the last page which is a single page on the right side. When you have two pages side by side, the gutter is in the middle of the two pages so that it's readable when the physical magazine is bound. Sometimes, artists will put big reveals on the right-side page so you don't accidentally spoil yourself by glancing over when you have the book open to two pages.
It appears the default changed to page 1 and 2 facing each other instead of page 1 by itself and pages 2 and 3 facing each other.
This doesn't appear to be the case on chapters that have 2 page spreads because I guess the reader will start with 2 pages that have to face each other and work its way in pairs to the beginning/end of the chapter.
But it's worth noting that for non-magazine chapters (doujinshi/books/digital-first releases), the page parity may be different due to cover pages, etc. so if the only way to change page parity is with double page spreads, you should make it a feature request to be able to set the parity, I suppose.
tl;dr: most magazine chapters in "two pages when possible" mode should be 1, 2-3, 4-5, etc. but the majority of them today are 1-2, 3-4, etc.
This is still a problem, btw. It's exacerbated when a chapter has improperly flagged two page spreads because opening in "two pages when possible" mode will split the spread in half