Delete multiple attachments from conversation in iMessage WITHOUT deleting the conversation.

I want to delete multiple attachments, images that I sent people using iMessage, because my iCloud storage runs out of space.

In other threads it was suggested to go iMessage -> Contact -> Info -> Mark multiple Images -> Delete.

This does not work, it will only delete one of the Images.

Please explain how to delete multiple Images/Attachments WITHOUT deleting the conversation.

I uploaded a video of the process.

https://www.youtube.com/shorts/4UmfuKTdNMY

I hope someone can help.

macOS Monterey 12.4