PDF Templates Quotes - Discount Amount showing incorrectly when $ value above 1000

When creating a PDF Template for Quotes I have noticed the following.

When using the following $aos_products_quotes_discount to show the Product Line Item Discount amount and $aos_services_quotes_service_discount to show the Service Line Item Discount amount - if the amount is <$1000 then the amount is correctly displayed if it is >= $1000 it is incorrectly shown

example $1000.00 shows as 1.00

Quotes - Edit View and Detail View are all correct, the Total Discount for the whole quotation is correct in all View and PDF.

I have also tested this with the Sample_Quote PDF

I am wondering if there is a coding error somewhere with regards to format X,XXX.XX - I am happy to do the testing if someone can let me know where this script may be hiding