Hi squidlet2.
welcome to this Apple (user-to-user) Community.
Re: "Apple TV won't stream after account update : I have recently changed my email address, and went through the Apple account information page to update and change my password."
Wondering if you are still signed in to Apple tv with those older details ...
if so, you may need to sign out from Apple TV, and / or sign back in with the updated details,.
To check you are signed in to your Apple Account with the correct Apple ID:
Sign in to your Apple Account on the web or in your device settings - Apple Support
Eg: says:
"Sign in on your Apple TV 4K or Apple TV HD
- Open the Settings app.
- Go to Users and Accounts. Then choose a Suggested User or select Add New User.
- Choose a method to sign in:
- Use Another Apple Device: If you have an iPhone or iPad that’s signed in to your Apple Account, bring that device nearby and follow the nstructions on both devices to complete sign-in.*
- Sign in Manually: Enter your Apple Account email address or phone number and your password. If prompted, enter the six-digit verification code sent to your trusted device or phone number to complete sign-in.
Learn what to do if you can’t sign in
* To sign in with another Apple device, Bluetooth must be turned on for both devices and both devices need compatible software. If you don’t see the option to Use Another Apple Device or it isn’t working, update to
the latest software version on both devices."
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Resource for TVOS 26: Apple TV 4K User Guide - Apple Support
