Hello AccountsManagement,
This can happen if your child knows or guesses the Screen Time passcode. Another way is if they requested additional time for the app that another parental figure has received and approved.
We would encourage you to change the Screen Time passcode: Use Screen Time on your iPhone, iPad, or iPod touch
To change or turn off the passcode on your child's device, go to Settings > Screen Time and tap your child's name. Then tap Change Screen Time Passcode or Turn Off Screen Time Passcode, and authenticate the change with Face ID, Touch ID, or your device passcode.
You can also check if another parental figure approved the request, by simply asking them.
It's also important to stay updated for the latest fixes: Update your iPhone or iPad
Let us know if this helps out or not.
Take care.