Did you set them up through the Apple family share setup? That seems to be the reason why we're getting the error when we try to add a 2nd line through the family setup.
Currently going through the exact same experience. For 3 weeks they would tell me to wait for a call back in 24-48 hours. The last person told me to wait 3-5 business days. I already have a watch line activated so none of my kids have been able to us...
