Sometimes when you connect Apple Pencil 2 to iPad, the battery level is not displayed, only «Apple Pencil» notification appears and the screen does not recognize the pen.

To fix it:

• remove the pen from the bluetooth device list;
• reconnect the pen to the magnetic connector;
• restart iPad with pencil on magnetic connector.

In some cases it works after 2-3 times.

Be careful. It can indicate about damaged Apple Pencil battery or the pen itself.