I don't know if this is new or not, but the left and right margins on this epub are messed up on my kobo. They extend out beyond the edge of the screen. The one with no images. I opened it in Sigil and fought with the css and could never get it to display properly but finally figured out that adding a cover image fixed it.
(The epub with no images.)
https://www.gutenberg.org/ebooks/40693