- If you click slowly (click-hold-release) on a pop-up search result, the search results disappear but you don't get taken to the desired page.
- If you click quickly (click-release) on a pop-up search result, then you get taken to the desired page as expected.
The animation below shows a slow click (which failed to navigate) followed by a fast click (which successfully navigated). It was recorded on the Qt Forum, but the same behaviour occurs on https://community.nodebb.org/ (Tested today, on Firefox 86.0 and Chrome 88.0.4324.190 on Windows 10)
I believe this occurs because a mouse-down event causes the pop-up to disappear. However, if the clickable link disappears before the user releases the mouse button, then the click event does not trigger.