I was working on several projects recently and noted that main background sound of these VTs was not working at all (tested on 3 phones, 2 Redmi Note 4 and one Caterpillar, Chrome browser). Desktop version works okay. There are short sounds in one of these VTs, playded after clicking hotspots, and these sounds work well. What seems strange to me is that sound in these VTs was working well some time ago (about a week ago, maybe), so the reason may be in some Chrome update which broke Krpano soundinterface 'user screen tap waiting' code.
Here's the backbone example of this : http://vt.most-inform.com/bugs/sound/
Can anyone confirm this on some other mobiles (android and iOS)?