Quantity not populating on contract invoice lines

I am trying to understand why quantity is not populating on the contract invoice line of our contract invoices. My expectation is that the quantity would sum those transaction lines which are below?

You can see in the description that the invoice format is summing the transaction quantity based on the invoice format grouping rules (See below screenshot), but its not coming across on the actual quantity on the contract invoice?

This results in the quantity being sent to receivables defaulting to 1 for all invoices, instead of showing the appropriate quanitty.

Basically, on a given invoice, we would only ever have 1 project and 1 contract line being invoiced, and we group by expenditure type for billing purposes, the example below has only 1 unique expenditure type, thus all three transactions are grouping into a single contract invoice line.