there is an ongoing discussion on the Alfred forum here but I did not see any solution
I just experience the same issue on Synology NAS (DS 918+). I am running Monterey 12.1 on M1 Mac Mini and Alfred 4.6.1. I believe the macOS , Alfred and DSM of Synology are all most up to date but not on beta.
I have included the screenshots showing Alfred and Spotlight search result as well as the Alfred troubleshooting result plus metadata of the file (just an example)