https://agscomics.com/series/reincarnated-as-the-mastermind-of-the-story/
If you looking for all translated chapters for this manga, it can be found here.
Check the official source if you looking for most the chapters in English, the uploader here seems incompetent.
If you go back to chapter 12, it has one page marked as 11, i forget when but there are was extra chapter that was either unnumbered or became a extra of a different chapter which is why we got a strange chapter count but anyway, today new chapter is actually ch14, we got a missing chapter.
It like they used google translate without thinking of how each character would speck.
The original manga is from ch1 - 13.
Alternative starts on ch14 but it by a different artist. Note that you can find ch1-40 of alternative on ‘mangaup’
Is this the latest chapter out? We were getting chapters daily till a halt, wondering if it been caught up?