QML MessageDialog with RichText does not show up in an UWP application

When having a MessageDialog with RichText in it, the MessageDialog is not shown in UWP application. With normal desktop application the dialog is properly shown. The following warning is given when using the RichText in the MessageDialog in UWP application:

qt.winrtrunner.app: Rich text detected, defaulting to QtWidgets-based dialog.

If the same dialog has no Rich Text in it, the dialog is properly shown.

Steps to reproduce:

• Run attached sample
• Press "Open MessageDialog" button
• EXPECTED: Dialog is shown with bold text in it
• ACTUAL: No dialog is shown