Game keeps reverting to windowed every time I Alt+Tab.

[Phaxtolgia]

Seriously this is getting annoying. Anyone knows how to bypass this?

[🪻🧋Sylvie💮🍃]

Hold down Alt+Enter key to switch between Windowed and Fullscreen mode.

[EscapeRouteBritish.com]

I get the same thing when I play in Big Picture on Steam Link, the next time I fire it up on my PC it's windowed.