Going into more detail would be helpful: Do you get an error? Do some settings restore or change? How old is your backup (i.e. from what version of Voyager)? Android or iPhone (before and after)? Are you selecting a file from your device, or trying to use from cloud storage (Google Drive, Nextcloud, etc)?

If you email me at hello@vger.app with the file I can take a look.

Disappointing, even.