Channel admins can't create child

I have a problem with my channel admins

I want to make them able to create sub-channels to the channel they are the admin of, however, this I can not do.

I have given them the b_channel_create_child permission, however, it does not allow them to create a sub-channel, the option is greyed out. Since they can't even click the option, I have a hard time figuring out which permission negates their ability to create a child channel.

Hope anyone has any clues as to what causes this problem.

I do not have any skip flags enabled for the Channel admin or any server groups besides Server Admin.

Channel admins can't create child