Btw, in case the cause/fix isn’t known, the issue is that external links will only open if the click event default behavior is allowed, but the markdown preview’s “close on click” handling prevents the default behavior. To fix this, MarkdownPreviewRenderer’s
onExternalLinkClick() could call
stopPropagation() on the click event (so it doesn’t bubble up to the level where the default gets prevented), and then explicitly close the preview. This would allow the default behavior to fire and the preview to be closed.
(Incidentally, doing a stopPropagation in its onCheckboxClick method to keep the preview from closing when you tick a box would be nice, too! It’d be especially useful when doing task searches and previewing the results.)
Alternately, just giving hover previews an explicit closing X and only closing them on link clicks or the explicit closing X (or by mouse out, of course) would avoid the issue entirely, and support plugins having more active UI accessible in hover previews, without the need to code explicit propagation stops for every possible interaction.