Trouble adding iPhone to Second hub?


Im having trouble adding my iPhone as a presence sensor on the hub at our weekend place. I get the message “Warning! This mobile phone is already set up as a mobile presence device.” Which makes sense, because its a presence sensor on our first hub, but it gives me no option to add it to the second. My girlfriends phone which is a Nexus 5x, did not have this problem.

Any thoughts?