When a PaperMenu is closed, sometimes the clone of the content used for the fade-out transition/animation remains in the DOM after reaching full transparency, preventing clicking on content below it - which can include the trigger, giving the impression that the menu is refusing to reopen.
This has only been observed in Firefox, when clicking outside the menu to close it; the behaviour is inconsistent, and the fade-out generally doesn't (visibly) happen in the cases where the transparent clone remains in the DOM. It appears to be a timing issue, where the transitionend / animationend event listener isn't attached (by waitForAnimations()) until after the clone has already become transparent, so the event listener is never triggered.
When a PaperMenu is closed, sometimes the clone of the content used for the fade-out transition/animation remains in the DOM after reaching full transparency, preventing clicking on content below it - which can include the trigger, giving the impression that the menu is refusing to reopen.
This has only been observed in Firefox, when clicking outside the menu to close it; the behaviour is inconsistent, and the fade-out generally doesn't (visibly) happen in the cases where the transparent clone remains in the DOM. It appears to be a timing issue, where the
transitionend/animationendevent listener isn't attached (bywaitForAnimations()) until after the clone has already become transparent, so the event listener is never triggered.