Hi there,
I'm using Alfred v3.8 [959] with Power Pack on macOS 10.13.6 and I'm experiencing issues with launching some apps:
/Applications/Whatsapp.app for example can't be started from Alfred, but can be launched from Spotlight.
Some other apps that can't be launched:
/Applications/HP Easy Scan.app
/Applications/Micro Snitch.app
/Applications/PassMaker.app
/Applications/Pixelmator.app
/Applications/iBooks.app
It seems completely random to me.