UI Widgets lack cursor

Before I noticed that sometimes cursor was hidden when I was using UI Widgets with “requiresCursor”.
Mouse movements don’t move camera (as expected) and clicks in proper places lead to expected resuls, but cursor itself is not visible.
That usually was happening right after clicks (randomly).

Now cursor is never shown and it’s impossible to build proper UI.

UPD: that happens when clicking in the <input type="text"/> element. Once clicked there - preview will never have cursor until full restart.