Wonder if it is a US vs. ROW effect?
Nah, don´t think so. The WordPress architecure is pretty open. I´d rather think that´s a browser or anti-virus thing. Maybe the drop-down plug-in is getting in conflicts (like identifying it as pop-up) and blocking it. Pretty sure it´s the FireOS thing I experience. It works on all my other things, including the Android phone, nicely.
"In strange grammar this one writes" - Master Yoda