AirPods and AirPods Pro automatically switch between iPhone and iPad. If you turn off the iPad and start a call on your iPhone, it will automatically switch to your iPhone. Don't like this feature? See how you can turn it off.
How AirPods work automatically
This feature was added to iOS 14, iPadOS 14 and macOS Big Sur. If your iPhone or iPad has been updated to its latest version operating system and AirPods are in your ears, switching devices works automatically. (If not, try updating firmware on AirPods or AirPods Pro.)
Automatic switching works with AirPods (2nd generation), AirPods Pro, Powerbeats, Powerbeats Pro and Solo Pro.
In the traditional Apple sense, it "just works." You do not need to enable this feature. When AirPods switch between devices, you will see a small one notice about it. If you want, you can press the blue "Back" button to return to the previous device.
How to turn off auto-switching for AirPods and AirPods Pro
If you frequently use iPhone, iPad and Poppy together (for example, while you work in your office), it can be annoying when AirPods automatically switch between devices.
Fortunately, you can turn off AirPods switching and return to manual switching between devices.
You must disable this feature per device. First, connect the AirPads to your iPhone or iPad and open the "Settings" application.
On the Settings screen, tap the "Bluetooth" section.
Now, find your AirPods from the list and tap the small one icon "I" next to your AirPods.
Here, select "Connect To This iPhone" or "Connect To This iPad", depending on your device.
From this section, select "When Last Connected To This iPhone" or "When Last Connected To This iPad".
You have now turned off the automatic switching feature for AirPods. Go to your iPad and repeat this process.
How to switch devices manually
You can switch between iPhone or iPad manually using the Control Center. Swipe down from the top right corner of your iPhone or iPad to reveal the Control Center.
Here, click the small "AirPlay" icon to display all available ones Appliances.
Now select your AirPods to switch between them.
Source of information: howtogeek.com