Quarantined item not in quarantine store

I quarantined a double extension file that AV picked up because I was doing something else and wanted to look at it. When I wnt to the store the cupboard was bare!

Anyone else experienced this?

I just got the same again today and managed to prevent hte AV from deleting the file, and then when the program runs the firewall says the program is safe and signed by Google. Why can’t the AV pick this up?