Click on font selector (button marked “Verdana Bold 60” in the following image):
Works fine, dialog box appears.
However, if you DOUBLE-CLICK on the font selector (step 2) by mistake, the dialog box disappears.
I found it hasn’t gone completely, it’s now BEHIND the main SC window.
I have experienced this, too. I guess you could call it a bug. Unfortunately, UI behavior like that is under the control of the Qt UI framework that Shotcut uses. It is unlikely to be something that can be fixed in the Shotcut code.
Click anywhere outside of that font selection box, and the dialog box goes behind Shotcut. I have to hover my mouse over the taskbar in windows to bring it it back up. As long as I stay on the font selector box, I’m fine, it stays on top.
If I drag the font selector box to a different monitor (I have two monitors), it still acts the same way, if I click something other than Shotcut, it fall behind what ever window I click on the 2nd monitor.