I notice when visiting your page (in a desktop browser) that if you check the browser console you will see there are multiple JavaScript errors, arising from core JS files that are included with WordPress.
That may be preventing layout code for the collage display from executing.
Could you please test whether the errors disappear when you disable the non-Toolset plugins? (You might want to start with any optimisation plugins that may affect what JS is loaded on the page and how.) If there is still a problem, check changing theme to a standard theme like twentytwentyone.
If you eliminate the JS errors and the collage display still does not work we can take a closer look to try to identify why.