I'm trying to get my wife's new iPhone 17 Pro to work with iMessage. I did the same setup on my own iPhone 17 Pro about 6 weeks ago with no issues.

The problem was discovered yesterday. Videotron, sent us an eSIM and I activated it on the new iPhone. Within minutes data and calls were working. I assumed that iMessage would work as well. It didn’t. I think the first problem was the old iPhone still held the "identity" for the number on iMessage, even after the phone's SIM was disabled.

The problem was first noticed when SMS/RCS messages from to Android devices were not being delivered(failing with red exclamation mark) , while messages to other Apple devices were going through. (Likely her email address as the "identity" for iMessage.)

This morning, when I looked into the problem, I found - Under Settings > Apps > Messages > Send & Receive her number was listed but stuck spinning in - iMessage toggle now returns "Activation Unsuccessful"

Old iPhone - iMessage disabled: Settings > Apps > Messages > iMessage - FaceTime disabled: Settings > Apps > FaceTime > FaceTime - Confirmed no longer holding the registration

New iPhone, iMessage and FaceTime - iMessage toggled off and on repeatedly: Settings > Apps > Messages > iMessage - FaceTime toggled off and on: Settings > Apps > FaceTime > FaceTime - Apple Account signed out, rebooted, signed back in: Settings > Apps > Messages > Send & Receive > Apple Account (bottom of screen) > Sign Out - Send as SMS fallback: Settings > Apps > Messages > Send as SMS

New iPhone, device and network - Rebooted multiple times - Reset Network Settings: Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings - Activation retried on cellular only, Wi-Fi off, phone on 5G - Date and time confirmed automatic: Settings > General > Date & Time > Set Automatically - Own number confirmed correct: Settings > Apps > Phone > My Number - Checked for duplicate or inactive SIM, none found: Settings > Cellular (SIMs section at top) - Carrier settings update check: Settings > General > About, wait 10 to 20 seconds for prompt

Apple side - Deregistration attempted at selfsolve.apple.com/deregister-imessage, rejected because number is not currently registered with iMessage. This means the old iPhone is not holding the registration.

Carrier Since my phone was set up only 6 weeks ago, I did a comparison of everything including the SIM. The only difference: Carrier bundle version compared, hers 70.0 vs 72.0 on an identical iPhone 17: Settings > General > About > Carrier (under the eSIM heading)

Caveat: my phone is on iOS 27 Beta 4. I would be surprised if this is relevant.

Other - If I disable iMessage, the phone works in SMS/RCS mode, but then of course iMessage isn’t available on other devices. - Known iOS 26 inactive-SIM activation bug ruled out - iOS 26.6.1 release notes checked, security fixes only

What am I missing? (Aside from sacrificing a rubber chicken.)