The bug report might not be applicable, I think the problem there was showing the message dialog "too soon", i.e. while the application was not fully ready yet.
My guess is your dialog is triggered via user interaction.

Have you tried a very minimal example, just some UI for the user to trigger the message dialog?

Cheers,
_

P.S.: don't concatenate runtime data into a translated string, positioning will depend on the translation. Use the arg() mechansim instead