Free Admin Account

Dear all,

I am having issue as one of users can't accept invitation to join Zoom account.

I have created free zoom admin account and invited 2 users  to have option to change background / add banner to camera view.

First one went smooth, but second account after accepting "to join new account and transfer account information"  received error "account is not paid ".

Do anyone knows if there is a limitation to manage users with free admin account?  

Kindest,

MA