LogCore: Display: AppLifetime: Application will enter background

For a VR game, I have some players sending me logs that show their game entering background state (it flashes to foreground a few times but always goes back to background and stays there for bulk of their time in the game). It causes their game to basically stutter as if there’s a window sitting on top or it’s minimized. What might be causing the game to go into background state? I suspect it’s SteamVR (it used to force itself on top over any other application), but it’s hard to be sure as well how to remedy it.