Global Media: Is this a bug?

[Spelunky]

If a video starts with audio muted, then the Global Media button is not displayed. And if, during the video display, you enable audio, the Global Media button will appear.
Is this behavior correct? or is it a bug?

Also, would it be possible to keep the Global Media button always visible? being grayed out when inactive.

[#2]

I'd consider it as a bug because it's inconsistent. when the video starts with audio muted, the Global media controls should appear in the toolbar albeit grayed out.