How do I downgrade back to iOS 10.3.3?

Sorry, Apple does not provide a downgrade path for the iOS. Is there a specific problem you need help with?

Cheers,

GB

OK, so you are going to want to try a few things:

First, try a simple reset of your device. Hold down the Home and Power buttons at the same time and continue to hold both of them down until the Apple appears (up to 30 seconds). Once the Lock screen displays, see how things are working. If you are still having issues:

1. Back up your iPhone to iTunes or iCloud for later use

2. Erase your phone: Settings>General>Reset>Reset all Content & Settings

3. Set your phone up as a new phone (not from the backup) - sign into iCloud and other services as usual

See how the phone works as a clean device. If you are still having issues, then you may want to set up a Genius appointment to have it looked at.

If the issues seem to be resolved, then erase your device again, and this time set it up from your backup. The reloading of purchased media can take a bit of time, so be patient for the backup to complete.

Once it is ready to go, see how it behaves. If things are working as you would expect, then you are all set. If things have degraded again, then that implies that there is some corruption in your backup data, and you will want to erase your device, set it up as a new device, and then manually re-download your purchases.

Best of luck,

GB