Hi beansheaf-garage
Please check that you have all of the required VAT codes activated within QuickBooks by going to Taxes > Edit VAT > Edit rates > Select the small cogwheel > Tick 'include inactive'.
If any codes which you're needing show as inactive here please toggle them on.
After this, please disconnect and re-connect the app from within the Apps section to ensure the codes are mapped correctly during the setup.
If you're continuing to have issues following this, please reach out to Workshop Software to report the issue> https://help.workshopsoftware.com
Thanks!