Controller stops working when the game loses focus?

You are playing with a controller on one screen, you click a browser or Discord on the other, and the game stops responding to the pad until you click back. The game is doing that on purpose, and most games offer no setting to change it.

Why it happens

Windows tells a game when its window stops being the active one. Most games answer by ignoring controller input until they are active again, so a button press meant for another program cannot move your character. Games that read the controller through XInput are told to do exactly this: switch input off when the window deactivates, and back on when it returns. Windows Gaming Input, the newer controller interface, only delivers input to the app in front.

Free fixes first

1. Look in the game's controls or accessibility settings for an option such as "Background input", "Pause when unfocused" or "Run in background". A few games have one, and it is the cleanest fix when it exists.
2. Emulators often have it. Dolphin, for example, has a Background Input checkbox in its controller settings.
3. If you only need to read or scroll the other screen, skip the click. Turn on Scroll inactive windows when I hover over them in Settings, Bluetooth & devices, Mouse, and the game keeps focus while you scroll.

When the free fixes are not enough

Most games have no such option. Dropping input on focus loss is compiled into the game, so no configuration file changes it, and the moment you type in chat or click a link, the pad goes dead again.

How Second Screen Gaming fixes it

Controller assistance keeps the game believing it is still the active window, and keeps passing it your controller while you click, type and browse on the other screen. It works with 64-bit Windows games that read one Xbox-compatible controller through XInput or Windows Gaming Input. With two controllers connected it steps aside rather than guess which one belongs to the game.

It is experimental, and it works differently from every other fix in the app:

Read this before turning it on. Controller assistance loads a small helper into the running game to intercept its focus and controller calls. That can break a game's terms of service or trigger anti-cheat, multiplayer restrictions or an account ban. Second Screen Gaming switches it off for games where it detects anti-cheat, but detection is not a guarantee. Use it with single-player games, after reading the developer's terms. The app asks you to acknowledge this before the switch can be turned on.

Turning it off, or closing the tray agent, stops its effect straight away.