DialogHost CloseDialogCommand is not triggered by Esc due to unexpected focus behavior

[yoi102]

Bug explanation

As shown in the video below, the focus behavior of the DialogHost seems incorrect.

After clicking the dialog, pressing the Esc key does not trigger materialDesign:DialogHost.CloseDialogCommand, so the dialog remains open.

When pressing the Tab key, the focus appears to move to the content inside the DialogHost itself, rather than staying within the dialog. As a result, the content inside the DialogHost becomes focused/selected.

Video:
https://github.com/user-attachments/assets/58a8465d-cda2-44ee-a2bc-a11516511553

Version

5.3.3-ci1412

[corvinsz]

@yoi102 having a quick look at this with snoop, it seems like the button which opens the dialog handles the Esc KeyDown event.
A workaround for now is to use the Style="{StaticResource MaterialDesignEmbeddedDialogHost}" style for the DialogHost, which however restricts the dialogs dimensions to the height and width of the parent window.

This seems like yet another problem with the internally used PopupEx in the default style