Your system information

• Steam client version:
  
• Distribution: Arch Linux
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes

Please describe your issue in as much detail as possible:

Demonstrative video: https://youtu.be/VXksIC20aeg
Steam Big Picture takes input while in-game. This is not just sounds, but BPM is actually doing something in the background and can for example install or launch games. I have only tested with a steam controller. This problem is not limited to N++, it is just a lightweight game that is fast to restart. There seems to be no clear cut pattern, but there is a trend that if you do not press anything immediately at game start or if you open the configurator before inputting in-game actions, the bug might not happen.

Steps for reproducing this issue:

1. Start a game while Steam Controller is on
2. Press the A button on the controller

Results

You should hear BPM in the background.