Encrypted backup password when didn't set password or set as encrypted

If you cannot access your encrypted backup on iTunes for your iPhone because you never even selected the encrypted box and set a password, yet iTunes keep asking you for a password, you can try the passcode lock for your current iPhone or old iPhones. It surprisingly worked for me.

My story was yesterday my iPhone XR was updating through iTunes on my mac pro and then the update freeze towards the end. I had to force restart the iPhone but upon opening, all my information are ALL gone like a brand new iPhone. I tried to restore backup from iTunes but the backup was "encrypted" but I never set it as encryption. so it was impossible for me to have a password. I tried all possible password i can think of. I click the encrypted box and try to set a new password, which iTunes allowed me to do and then tried the newly set password for the backup: still didn't work. Then i try to cancel the encryption option but it require me to input the password to cancel the encryption, yet the newly set password didn't work either. Eventually, the old passcode of my older iPhone worked so worth a try for those who have similar problem as me.

I read the post on apple community and other user seems to have similar problem as me but apple support was not helpful at all. The replied post from apple just refer you to their post on encrypted backup and tell you to double check if your backup is really encrypted and tell you to try to remember your password. Apple really need to fix this bug because i didn't set a password and i didn't set backup encryption.

However, i later had trouble with completing the backup: iPhone froze again during the backup when completing and it took me like 2 more other times to attempt to restore backup for it to finally work. Wasted one and a half day of my time.

Long story short: apple need to fix problems with its new updates, with the encrpyted backup (like have a forget password option at least or something and not automatically set one for user when they didn't ask for it), fix bugs with restoring backup too cause my iPhone froze and was stuck on the flashing apple screen 3 times and each time, i couldn't even force shut it.