Retrieving media and restoring conversations from iCloud backup

Photos and videos were removed from old messages by icloud backup and won't restore when I sync. How do I retrieve this media and restore these conversations?

iCloud has 50gb of data stored in it from messages, so it seems like that data is there. I want to retrieve the data and shut down my icloud backup but don't want to lose that data. Apple support says this is an ongoing issue and to just keep subscribing to icloud backup until it's fixed, but in the mean time photos and videos continue to disappear from my old conversations.

I'm using an iPhone 16 ios 18.7.1 and a Macbook pro 2024 - 15.6.1

[Edited by Moderator]