Screen Time Backup Apple ID Not Working

I’ve set a time limit on my sister’s ipad, and wrote down the code that was set. Recently, I’ve tried to unlock this limit but when I try to enter the password it says it’s incorrect even though I know it’s what I entered. Luckily, I had set my Apple ID email and password as a backup incase somehow I had lost the password, but when I enter the Apple ID and password, it just brings me back to the failed code UI. I’ve even reset my apple ID’s password and reentered it with the new one and it still brings me back to the code entering area, and adds another failed attempt each time I try to enter the backup ID. Please help me out.