Help. Discount image badge on all items

-- HikaShop version -- : 2.4.0

Hi,
I tried setting up a coupon for money back for one item (the shipping cost)- all appeared to work correctly. However, I noticed that the badge is showing up on every product picture.

I unpublished the coupon - image remained.

I deleted the coupon. Image remained

I have gone into the server and deleted the image, resulting in the default 'no image' picture (the ticket) being in the place instead. However, it is still showing as free p&p when you hover the mouse over - not good. (image below)

While this would appear to be a caching issue - I have the site set to caching disabled.

Can you help at all? It doesn't make sense as there is now no discount using this badge on the system.