Why does my iphone ask for my passcode every time I sync it to trust my computer.

Hello corellifan1,

The information provided by Apple Support is correct, and can be found in Using USB accessories with iOS and iPadOS.

Starting with iOS and iPadOS, if you use USB accessories with your iPhone, iPad, or iPod touch, or if you connect your device to a Mac or PC, you might need to unlock your device for it to recognize and use the accessory. Your accessory then remains connected, even if your device is subsequently locked.

If you don’t first unlock your password-protected iOS or iPadOS device—or you haven’t unlocked and connected it to a USB accessory within the past hour—your iOS or iPadOS device won’t communicate with the accessory or computer, and in some cases, it might not charge. You might also see an alert asking you to unlock your device to use accessories.

If you're wanting to allow access to your device without entering your passcode, you'll need to manually enable that setting.

1. Open the Settings app.
2. Go to Face ID & Passcode.
3. Turn on USB Accessories under Allow Access When Locked.

Cheers!

Hey there corellifan1, 

Let's take another look at Using USB accessories with iOS and iPadOS,

"Allow access to USB accessories

You can allow your iOS or iPadOS device to always access USB accessories, for example, if you use a USB assistive device to enter your passcode on your locked iPhone. Many assistive devices will automatically turn on the setting to allow USB devices the first time they’re connected.

If you don’t connect to USB accessories regularly, you might need to turn on this setting manually.

In Settings, go to Face ID & Passcode or Touch ID & Passcode, and turn on USB Accessories under Allow Access When Locked.

When the USB Accessories setting is off, as in the image above, you might need to unlock your iOS or iPadOS device to connect USB accessories.

Administrators can control the USB Accessories setting on supervised iOS or iPadOS devices using Apple Configurator or mobile device management."

If you have followed these steps, and are still prompted for your passcode when connecting your iPhone, you may need to test using a different cable, port, or connecting directly to your computer instead of using a hub, if you currenlty are.

Have a good one!

We don't know. As I posted earlier it appears to be a protection measure against a newly uncovered exploit.

See https://imazing.com/blog/ios-backup-passcode-prompt. It likely won't change while unapproved backups would still present a security risk. You could do what I do, which is to backup to iCloud automatically, and take the occasional manual backup on my computer.

tt2

It appears to be a protection measure against a newly uncovered exploit.

See https://imazing.com/blog/ios-backup-passcode-prompt.

tt2

Hey corellifan1,

If the issue is still occurring, reach out to Apple Support at the following link so they can look further into this with you:

Contact Apple Support

Take care. 

I'm having the same issue after the update and it's a nuisance. Did you ever figure out how to add the USB accessory button or some other fix. Thank you and thank you for posting.

Thank you.

Still happening to me here. such a bummer

It even happens when trying to sync via Wifi.

When will apple remove this? We should only have to approve a backup once. It’s a real nuisance.