Portrait vanishing issue

[Digital Mosaic Games]

Hey guys,

We are using the sierra (transparent) speech style in AGS. In our dialogs when there are no more options to select
AGS run the "Exit" dialog automatically. Now whenever there are no more options to run and AGS run the "Exit" dialog
we can see the portrait disappear for a moment and then it appears again. Is there a way to avoid that short
disappearing of the portrait?

We are using AGS 3.4.1P4

Thank you!