Sale price not showing on collection page

[StupidPetStuff]

Hi Everyone, 

I am using the Dawn theme, and I use Oberlo to import items. 

When I use the compare at price before importing with Oberlo, there aren't any issues. 

However, when I change the compare at price on Shopify, the product page does the right thing, but the Collection page does not show the item is on sale. 

I've had a scout around on this forum and the web and I cannot find a solution, and I am no where near proficient enough to edit any code. 

Can anyone help?