Hi Lux41,
Thank you for reaching out to Microsoft Community.
Surface Earbuds can be paired up to 7 devices but it can only be actively used on 1 device at a time which is your last paired device if it is in range. Otherwise, it will pair to the device in the order you have last used. You may also control which device will be used by going to the Surface Audio app > Device Setting > Paired devices. You will have the list of devices that was paired with your Surface Earbuds and you'll have the option to toggle which device will be connected.
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.