This is happening for me as well. Mainly in Firefox.
Chrome and Edge do also have this problem. But after re-posting the page with the masonry grid. And after emptying the cache. It seems like the problem is gone for Chrome and Edge.
Only Firefox seems to be a problem. Although in Firefox the problem does not show in Preview mode for a page. Only after the page has been published.
My page with this problem is: https://arcticadventure.nl/expedities-overzicht/