Cannot create child account through Family Sharing

I have tried to create a child account numerous times on each of three different Apple devices (iPhone 11, iPad 9th Gen, Macboook Pro [2023]). I've updated and restarted every device, yet nothing works. Every time, after going through the entire process, I get the message "Could Not Create Account / Your account cannot be created at this time". There are no other error messages. My internet connection is stable. What else could be going wrong?