Issues with sorting a summary of invoices

Title

Issues with sorting a summary of invoices

Post

     I am building a database with invoicing included. As I am a noob at FM I have more or less copied the Invoices starter template from FMP12 and inserted it into mine. Most things work, however, the summary list of invoices does not.

     In the template in the layout "Invoices", the invoices are summerised by a Sort List Key and displayed according to Company, Invoice ID, Payment Status or Date, whichever you choose. The problem I have in my DB is that in the equivalent layout, only the last created invoice record is displayed and I don't know why. In the status bar above for the records it says this is record number 3 and next to the green pie thing says "5/8 Found (Sorted)". I have a feeling it's a sorting issue but I don't know where to find the solution.

     I have uploaded a screengrab to show what I mean. The blue one above is mine only displaying one record, the grey one below is the FM template showing multiple records.

     Help please!