hiii it should work at any zoom, the grid automatically resizes once the page finishes loading to fill in any gaps/match the viewport. it could be a loading time thing? sorry, not really sure what the display problems could be otherwise. i've tested the site pretty extensively on diff browsers & zooms w/o issue so i'm not sure how to recreate the problem you're having.
there is a specific issue in which if you switch the theme, the content might look odd because all the fonts are different which leads to sizing differences. in which case refreshing the page will fix it. but other than that i'm not aware of display issues. sorry about that though!
your themes are so cool I'm in love