When the game is paused, then you press alt + tab or just touching the taskbar to unfocus the game window, when you refocusing the game window again the game will momentarily unpause, this seems to only happens when you're on pause screen, doing the same things while on other screens (for example, Dressing Room) doesn't momentarily unpause the game.
This also happens when you open any screens (Settings, Profile, Marketplace, Member Permissions, Dressing Room, Realms Stories, etc) and then go back to pause screen.
Steps to reproduce:
Method 1 (Windows only)
Pause the game
Press Alt + Tab or click the Taskbar
Now click the game window
Method 2
Pause the game
From the pause screen, open any screens (for example, Settings)
Go back to pause screen
Expected results:
The game keeps paused.
Observed results:
The game will momentarily unpause, then quickly pause again.
Linked issues
is duplicated by 6
Attachments
Comments 7

Also comes into effect when transitioning from any menu (vis. Settings, Marketplace, Dressing Room, Profile, Member permissions, profile screen) to the pause screen.
This issue also seems to happen when the game window is dragged via its titlebar or when the currently focused app changes. The game seems to un-focus and then focus itself as you can see in this video:
[media]This could possibly be related to MCPE-109879 which involves the game "realizing" that focus is being switched, and then suspending the app. In this case the game incorrectly "thinks" it's being unfocused when in reality it's not.