Hello dste202580,
Welcome to the Community - thank you for your question!
Do you have your bank connected? Are you creating the sales receipts through the banking page, or from the + icon? You can delete any duplicate transactions by selecting them, clicking More at the bottom then Delete.
To be clear, any transactions with the Exempt code will still show on the return, they just won't increase or decrease the VAT amount due. If they should not show, the code used needs to be No VAT.
Thanks,
Talia