Recover my original maps

I recently got a new PC and transferred my Unreal Editor for Fortnite (UEFN) setup. After signing in with my Epic Games account, I can see the names of my previous UEFN projects in the Project Browser, but when I open them, the islands appear empty — all of my previous work (landscape, props, devices, etc.) is missing.

I would like to know if there is any way to recover my original maps or files from Epic’s servers, especially if they were previously uploaded or synced with my account.