I can not use airpods and magic mouse in same time

Hello oulutas,

Thanks for choosing the Apple Support Communities. This sounds like wireless interference that may be causing your devices to run slowly or not provide the input you're looking for. Here are some steps that may help.

Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support

"Wireless interference can cause Wi-Fi and Bluetooth devices to disconnect or perform poorly, but you can take steps to reduce or overcome it.

Symptoms of wireless interference

Any of these symptoms could be caused by interference affecting the Wi-Fi or Bluetooth signal:

• Device doesn't connect or stay connected
• Connection is slow and signal strength  is low
• Bluetooth audio skips, stutters, cuts off, or has static or buzzing
• Pointer movement is erratic or jumpy

How to reduce wireless interference

These general steps can help achieve a cleaner, stronger wireless signal:

• Bring your Wi-Fi device closer to your Wi-Fi router. Bring the Bluetooth devices that are connecting to each other closer together. 
• Avoid using your wireless devices near common sources of interference, such as power cables, microwave ovens, fluorescent lights, wireless video cameras, and cordless phones.
• Reduce the number of active devices that use the same wireless frequency band. Both Bluetooth and Wi-Fi devices use the 2.4 GHz band, but many Wi-Fi devices can use the 5 GHz band instead. If your Wi-Fi router supports both bands, it might help to connect more of your Wi-Fi devices to the 5GHz band. Some dual-band routers manage this for you automatically.
• Configure your Wi-Fi router to use a different Wi-Fi channel, or have it scan for the channel with the least interference. Most routers perform this scan automatically on startup or when reset.

If you're using USB 3 or Thunderbolt 3 devices with your computer, you can limit their potential to interfere with nearby wireless devices:

• Use a high-quality, shielded USB or Thunderbolt 3 cable with each device.
• Move your USB 3 or Thunderbolt 3 devices—including any USB hubs—farther away from your wireless devices.
• Avoid placing USB 3 or Thunderbolt 3 devices on top of your Mac.
• Turn off any USB 3 devices that aren't in use.

Avoid physical obstructions in the path of your wireless signal. For example, a metal surface between your Bluetooth mouse and computer could cause the mouse to perform poorly, and a metal-reinforced concrete floor between your Wi-Fi router and Wi-Fi device could cause poor Wi-Fi performance.

• Low interference potential: wood, glass, and many synthetic materials
• Medium interference potential: water, bricks, marble
• High interference potential: plaster, concrete, bulletproof glass
• Very high interference potential: metal"

We hope this helps.

Cheers!