Restoring GarageBand project from 124 MB backup file in iPadOS 18.6

I recently upgraded my iPad Pro (A12X) to iPadOS 26 (not beta) and used it for about a week. However, due to performance issues — the system was noticeably slow — I decided to downgrade back to iPadOS 18.6.

Before downgrading, I made sure to backup all my data via iCloud while still on iPadOS 26. After successfully restoring back to iPadOS 18.6, most of the files came back properly (I’d say around 99.99%). However, I encountered an issue with GarageBand files:

• iCloud auto backup wasn’t working due to a mismatch (iCloud saw the latest backup as iPadOS 26), so I manually erased and set up iCloud again to back up everything fresh.
• In the iCloud section , I can see two GarageBand backup files:
  • One is 124 MB
  • The other is only 10 MB
• But when I open the GarageBand app, I can’t find any of my previous saved projects, especially the one I worked on right before upgrading to iPadOS 26.

I suspect the 124 MB file contains the missing project, but I don’t know how to restore or open it properly.

Has anyone faced a similar issue?

Is there a way to extract or import the GarageBand project from the 124 MB file manually into GarageBand?

Any help or insight would be greatly appreciated.

[Re-Titled by Moderator]

Original Title: GarageBand project missing after downgrading from iPadOS 26 to 18.6, found backup file but can't open