'Verification failed, unknown error occurred’ error on child’s iPad

Child’s ipad is linked to my Apple account via the Family setting. They have their own iCloud email linked to their account. When trying to update aps on their iPad, they are getting the 'Verification failed, unknown error occurred’ (the iPad used to update fine, just started this error two days ago.). My other child’s ipad, and mine are able to update aps. All wifi devices attached to our wifi are working properly. The password linked to my account is working on other devices. I’ve done a soft/hard reset, checked the network, iPad has latest update, but don’t want to sign out of my Apple ID unless I really have to in case that stuffs up.