Dynamic Custom Groups

I've created a custom group that;-

1. Checks is peace of software is installed
2. If that peace of software if exists isn't a version
3. If another peace of software isn't installed

This group seems to work but when attached to a configuration and deploys it, it does have the correct number of clients based on the custom group at the time of creation but the configuration isn't checking the custom group for new clients.

Is this normal and if so how can I get around this as I need to make sure that all equipment have this software installed.

Stephen Fowles
3rd Line Support Technician
North West Ambulance Service - NHS Trust