Converted to Family, but familymembers don't get premium

[Rickvd28]

Hi there,

 Two days ago I converted my premium to a family account and invited my husband to join. He accepted on his account but this stays in the free-modus. 

Checking my account, it is converted to family, he is a member. He removed the app on his phone, installed it again but, still freemium. 

• Anyone knows what he/we/I need to do to get his account to Premium for Family?

Thanks in advance & happy holidays!

Rick