So, I am strangely unable to replicate it. That being said, given the changes I made, I think I know a way to fix it, so please try again. If it doesn't work, please send me the full screenshot (probably linked to the size of your browser window). Thanks!
Not fixed yet. Apparently this now also occurs while I'm in the forum. Until yesterday it only occured in-quiz or from the dashboard. I noticed that stragely after I add a picture to a term, the pop-up comes down again and stays there until I reload the page.
didn't check if this is something only in the beta or already on the main site, but I just noticed that on the dashboard stats panel, each included panel shows two icons, one for graphs and an X.
Clicking the X makes it vanish without anything changing. Clicking the graph icon shows the corresponding graph and the icon vanishes, leaving the X if it was still there or replacing the graph icon with an X. So I guess there should actually only always be one icon and the graph and X icon alternate depending on a graph being shown or not, but the initial state the page is loaded has both icons appear for each item.