Yes, your X4 earbuds can pair to 2 devices, and remember 8 phone/music devices. When you turn on your X4 earbuds they will automatically connect to the most recent connected device.
Ensure your earbuds are up to date. Connect to the Jaybird App to see if a firmware update is available.
You can connect to two devices simultaneously, but play audio only from one device at the time.
To connect to two devices simultaneously follow the instructions "CAN I CONNECT MY X4 EARBUDS TO TWO DEVICES SIMULTANEOUSLY?".