We're on it. Nesting opacity issue from ignored fix is my guess (without looking) –
In a recent Stacks update, we applied a lower opacity to the children of
.s-post-summary when ignored or deleted. This styling affected the container of the tags (and everything in it including the tag popover). We've shipped a fix Stacks to apply the lower opacity more selectively which should resolve this issue. Please report any other issues if you find any and thanks for reporting @ShadowTheSpringWizard!
[…]due to wrong z-index.
Although we did not make changes to any element's z-index, giving an element an opacity less than 1 results in it gaining a new stacking context.
Since an element with opacity less than 1 is composited from a single offscreen image, content outside of it cannot be layered in z-order between pieces of content inside of it. For the same reason, implementations must create a new stacking context for any element with opacity less than 1. If an element with opacity less than 1 is not positioned, then it is painted on the same layer, within its parent stacking context, as positioned elements with stack level 0.