Can't edit contact details in Outlook Live

Since Microsoft "upgraded" Outlook Live a month or so ago, I've had problems editing details, such as email addresses and phone numbers, for people in my Contacts list. For instance, one contact's first name, last name, personal email, cell phone and two home phone numbers are editable: if I wanted to, I could put my cursor in the box and delete or type over them. But for some reason, the business number, which is no longer valid since the person is no longer employed, can't be deleted. The box is grayed out, and when I try to highlight the number with my mouse in order to delete it, the mouse doesn't work. This is true for other contacts in my list as well. Has anyone else had this baffling and frustrating problem?