Thank you for reaching out here in the Community.
If your family subscription was cancelled due to a failed payment in the past, the account may be on pause and that might be the reason why this is happening. Unfortunately, we can't make any account related actions here in the Community as we don't have access to such systems and tools. It's best you get in touch with our Customer Support team via one of the channels here about this as they can take a closer look into the matter and help you with your request.
Hope this helps,
Help others find this answer and click "Accept as Solution".
If you appreciate an answer, maybe give it a Like.