iOS 26 introduced a quirk that breaks iMessage for some users during iPhone setup. If you set up an eSIM after the initial setup process instead of during it, iMessage won't activate automatically, and you'll start seeing delivery failures, green bubble messages, or iMessages sent from your email instead of your phone number.
Apple just updated its support documentation to address this issue. The fix is straightforward: manually toggle iMessage off and back on after activating your eSIM. This forces the service to recognize your phone number and start working properly.
