Messages sending all messages to one individual as SMS, through iPhone only

[mrbrown]

This is a very odd problem that I’m having and it only occurs with one device (my iPhone) and one message recipient. We are both at our wits end trying to fix the problem.

We are both iPhone/iOS/macOS users, using iMessage - my friend is running 17.2 on all of their devices (and the latest release version of macOS on their MBP), and I am running 17.3 on all of my iDevices and the latest release version of macOS on my MBA & Mac mini.

When I message my friend through my iPhone, the message is never delivered and falls back to SMS. This only happens with this friend. I receive my friend’s messages through iMessage just fine (they’re blue).

However, when I send messages through any other device - my iPad or either of my Macs - they go through as iMessages every time, and they even show up as iMessages on my iPhone, which is iCloud synced.

We have both tried all of the following to no avail:

1. Signed out of iMessage.
2. Checked to see if we inadvertently blocked one another (we did not)
3. Signed out of iCloud.
4. Reset network settings.
5. Power cycled numerous times.
6. For me - turned off contact key verification (friend isn’t using it).

Again, this only happens with this one contact, and only when using my iPhone. Every other friend and contact receives iMessages as expected and they are delivered successfully.

Any suggestions, short of clean resetting the phone?

 

[teeshot44]

Only other thing I might suggest is to delete your friend's entire thread from your iPhone. Reboot and then try.

 

[mrbrown]

Only other thing I might suggest is to delete your friend's entire thread from your iPhone. Reboot and then try.

No dice. Has absolutely no effect. Still timing out and being delivered as SMS messages.

 

[mrbrown]

Strangely enough, disabling "Send as SMS" fixed the problem. Again, this was only occurring with one individual, and not any other users.