Designer: Edit text dialog of QPlainTextEdit shows on wrong screen in multiscreen-setups

UPDATE: I tried rebooting just in case, and after the bug is still there but with a twist, see notes at the end.

Steps to reproduce:

1. Create new QWidget forms application.
2. Open widget designer on the main widget
3. Put QPlainTextEdit into the widget. No layout or special placement necessary
4. Doubleclick the QPlainTextEdit to be able to edit text content

Expected:

Editor dialogue should open to allow me to type in my text for the QPlainTextEdit

Actual:

No window shows, instead QtCreator becomes 100% unresponsive to any UI. I can close QtCreator with ctrl+F4 keyboard shortcut. Once loaded again I can retry. QtCreator does not store project, indicating that ctrl+F4 actually killed the app.

Notes:

• QtCreator does not consume any resources like CPU/Memory. It simply acts as if there is a modal dialogue present, but there is none.
• Also I can move/resize the QtCreator window and the window will resize contents properly and responsively.
• The same happens if I invoke the dialogue by other means such as right clicking and selecting "Change Plain Text..." or if I press the "..." button in the property editor next to "plainText" property.
• If I type text directly into the property "plainText" it works as expected.
• The bug is reproducible 100%
• UPDATE: When I rebooted the same bug appeared, but this time the "Edit Text" dialogue showed up in the middle of my second screen (I have two screen setup). Suspecting the dialogue was just hidden, I had minimized all windows looking for dialogue before reboot but it was not present. After reboot it was in the middle of the secondary screen. I think this constitutes a "workaround" but really the logic for placement of dialogue boxes could probably need to be revised so they are at least guaranteed to be visible when shown.