Friend's location missing in iMessage but still shows in Find My

My friend's location is no longer showing up in iMessage. They still show in Find My, we have confirmed their contact information is identical on their end and my end, they still show up for their other friends in iMessage, and my other friends still show up for me in iMessage. I have tried the workaround of changing a label for one of their emails, one of their numbers, etc. and it does temporarily restore it, but it disappears again after just a few minutes. Is this just a bug that Apple has not been able to resolve yet?

[Re-Titled by Moderator]

Original Title: Friend Location Missing from iMessage