I recently ported my mobile number to a new provider (Australia Internode: Optus -> Vodafone). When I sent an iMessage to my partner her iPhone (iOS 15) showed the message as being from my number instead of my contact name.
Edit: Her phone also displayed: "The sender is not in your contact list", with a "Report Junk" link.
Her phone does now associate my number with my contact - perhaps after also swapping providers and restarting her iPhone - but the prior iMessage history from me is no longer displayed.
Does she have any options to restore the iMessage history?
Since she now has also similarly changed providers I want to avoid losing the iMessage history on my iPhone (iOS 10) and iMac (MacOS 10.13) when she sends her first iMessage to me. What are my best options to prevent losing the history, or being able to restore it if it should disappear?