The message "user changed their phone number" is repeated multiple times per day

• I have searched open and closed issues for duplicates
• I am submitting a bug report for existing functionality that does not work as intended
• I have read https://github.com/signalapp/Signal-Android/wiki/Submitting-useful-bug-reports
• This isn't a feature request or a discussion topic

Bug description

The message "Harry changed their phone number" is repeated multiple times per day per chat on the phones of other people in the chat/group, even though I only changed my number once.

Steps to reproduce

Here is exactly what happened:

1. A long time ago, I registered with a phone number (let's call it number "a") and chatted to many people, was part of groups, etc.
2. I got a new phone number (let's call it "b"), installed it in a different phone, installed Signal, and chatted to a few people
3. I deleted the account associated with phone number b.
4. I transferred the account for phone number a to phone number b.
5. My contacts see the message "Harry changed their phone number" many times per day. This happens in private chats and group chats. However, I am not updating my phone number: I only did this once.

I'm not sure if 2-3 are important or not, but I included them just in case its relevant.

Actual result: The message "Harry changed their phone number" appears multiple times per day per chat on the phones of other people in the chat/group
Expected result: The message should appear only once

Screenshots

Device info

Device: Google Pixel 4a
Android version: 11 / Security update 5 July 2021 / Kernel 4.14.212-gccfcc225a50c-ab7341516 / build RQ3A.210705.001
Signal version: 5.45.6

The versions and the screenshots above are from one of my contacts who is experiencing the problem. It is not from my phone (since I, correctly, don't see these messages at all).

Link to debug log

https://debuglogs.org/android/5.45.6/b9c9f15088a8f1737f000d1faa819e7a1fb25e986e1f2b8d528c2a5ac96c9974

Start by reviewing the linked debug log and reproducing the account-transfer sequence on Signal for Android, including the deletion and re-registration steps. Trace when the phone-number-change message is generated or delivered in private and group chats; done means the message appears only once after the number change.