No message sound for one iMessage correspondent? User message thread can be both silenced and not silenced.

I thought I'd fixed Emily's messages not generating a tone or haptic notification as per my 4/29/2024 post below. Then the bug recurred. It's fixed again, for now. I had to delete her iMessages - four times. To delete them I first unpinned her then swiped to delete all her messages [1]. Her entry vanished -- only to return a few seconds later. I repeated this 4 times; sometimes the messages showed her profile image and sometimes they didn't. ONE of the four times the message UI showed a mute/silence icon (speaker with a line through it). I un-silenced that one then again deleted all the messages.

Finally there were no messages left for her. When she messaged me it created a new message thread and notifications worked.

I did other things of course. I can't disentangle them all. I removed her Contact Card's iCloud.com email but left her me.com email (clue!). I quit and resumed iMessages (Messages.app) and Contacts. I set her Contact back to the default message tone.

But I think the important fix was removing ALL of her messages.

Here's my guess as to what's going on -- and why this bug will affect very few people.

1. It's possible for a Correspondent's message thread to be in a state of being silenced and not being silenced such that the silenced icon will not appear but the correspondent is silenced.
2. It may be that this bug ONLY impacts people who have both me.com and iCloud.com emails associated with a single AppleID (old time legacy users).
3. This bug is activated, I'm guessing, when a correspondent (Contact) is a participant in a group Chat that has been silenced and then un-silenced. (Because it showed up around the time I did that.)
4. Although we (usually) see only one message thread per correctly configured Contact, in reality it appears there are several identities merged to look like a single user. I had long suspected this, but seeing how deleting thousands of messages sent over a decade seemed to expose identities with different attributes strengthened my suspicion.

I'll update this post if I learn more or if the bug recurs.

- fn -

[1] I really didn't need any of that data.

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Initial version of this post from April 29, 2024

I got a message tone for every sender -- except Emily. Who is my most important correspondent.

So I went debugging. I asked Perplexity for fixes and got a good set of responses -- except for the non-existent DND setting (click for full res):

I tried all but reset Notifications since I have a vague memory of annoying side-effects from that. I also checked "hide alerts" (which is probably where the DND thing comes from -- that was an old term) on her Contact and that was off (not enabled). I toggled it for good measure.

I didn't want to remove and restore her contact as I thought that might mess up Photos.app naming. So I tried removing her phone numbers. Without any numbers in her contact iMessages did generate a tone -- but the default tone, not the custom tone. Still, it was something!

When I added in Emily's cellphone number that caused the custom tone I'd set to become active. (I also added back another number with no effect.)

So the bug is gone for now. I'm guessing it's something deep in the bowels of Apple's SMS/iMessage integration with AT&T (our carrier). The variable tone with and without the phone number is a clue.