“Oh hey, my old landline number is still in my Paypal profile, I should remove that.
There’s no option to remove it…”
Turns out that you *have* to have both a Primary Mobile and Primary Home number, and you can’t remove a Primary number. So, what you wind up having to do is add your mobile number *again* as a Home number, make it the Primary Home number, and then you can remove the old landline number, so you wind up with the same number listed twice.
This is not good UI design, guys!