Nesting a masonry gallery within a hide details element seems to break the post
[details="Summary"]
<div data-masonry-gallery>
images
</div>
[/details]
Turns out looking like this.
Substituting [grid] for the masonry gallery works, but does not preserve the row of images for mobile users. Is there a better solution available if I want to collapse multiple small galleries in a section?
Problem thread here
Windows 10
Firefox on desktop