Designer preview fails to show 'hidden' breakpoint

Early this year we had to temporarily hide some items from view on a client’s new site. We did that by setting the encompassing section to display:none.
Now the time has come to reveal them, we’ve set the section to display: block and published. This is true for all the breakpoints we have in our top Designer bar.

However, it turns out that between window widths 1420 and 1900 px, our section consistently disappears from view when looked at in several browsers (Windows, Mac OS; Chrome, Edge, Safari). With of course cache cleared etc. This type of behaviour is not there when previewing these sizes within WF preview, the section remains visible there. See the picture added: above is the WF Designer preview (running in Chrome btw) and underneath is the view in Edge of same site in Production not showing the 3 coloured blocks underneath the hero picture.

In effect, we have a ‘hidden breakpoint’ between window widths of 1420 px to 1900 px that we did not define but is active all the same. More disturbingly: since the 1420-1900 px zone is not a separate breakpoint in our Designer, we have no means of correcting the real-world behaviour. Any suggestions on how to solve this would be greatly appreciated.

I must add that this is not the only example I can give of differences between preview and real-world results.

Here is my site Read-Only: Webflow - SPIN- publieke site
(how to share your site Read-Only link)

When I added the 1440px breakpoint it does show that the section is set to display none. Not sure why that would be but you can fix it by adding that breakpoint and making the update.

Thank you very much!!