Popup behaviour not consistent

When I open a popup with code like this:

<a href="#" data-popup=".grafton" class = "show-more-button popup-open">More</a>

the calling page is dimmed and clicking outside the popup returns to the full page.

When I open a popup with this code:
the calling page disappears (except for the navbar and toolbar; clicking outside the popup does not restore the page.
I’d like the second call to behave as the first one. Suggestions appreciated…

Behavior for this two is totally the same under the hood. Issue must be somewhere else and more likely something wrong in your code

Thanks for responding.
Only difference in my code is one uses href and one uses app.popup.open.
I tried to use closeByBackdropClick to get some consistency but this does not seem to work (or I’m using it wrongly!).
Perhaps you could clarify how/where to use closeByBackdropClick for a single popup?