Last night my brother and I I booked our multi-family vacation for March. I The My Disney Experience I can see my reservation, but there is no 'Customize Magic Band' link. My brother was able to do the bands for his family, but I can't. Any ideas???
I know that you can't do it on the app... not sure if you were using the app or the website. Just an idea
The customize feature is only available in the account from which the booking was made. If it was done under your brother's account, they will need to be customized there. They will still show up in yours though.