When I open a saved backup in discohook, it seems to unlink immediately, here's a video.
What usually occurs, and what i expect, is the backup of a message to automatically stay linked to its associated backup.
The issue doesn't seem to occur on the majority of my backups, but for some reason one in particular has it. Here's a safe share link of the message in question if it may be helpful or relevant.
discohook/discohook