"New Products" images not showing

After recently upgrading from 3.8 to 3.9 all of the images on the website stopped displaying and were replaced with the default.png (camera) image. I responded to a topic already covering this problem but got no reply, so instead we spent all weekend replacing all the images on the website again. They are now showing, BUT, we now have a new problem. The "New Products" section on the home page (and the New Products page itself) still will not show the images that we have just added. For some reason they do appear for around half a second, and then disappear to be replaced with the default.png image again. On inspection of the pager code, it also shows the img src as the correct image as well. Can anyone tell me what seems to be overriding the images from showing please?

What's the site URL?

https://www.extremecreations.com.au/

After a few more days of trying things it appears that if the product is shown as "Mark as New" and also "Show on Homepage" it does not show the image on the home page for some products. Does this point to something that I can rectify?

Eventually cracked it. The website has a Nop-Templates theme that includes "Ribbons". In the upgrade all the ribbon Image URLs were replaced with default.png also.This image is then being displayed over the top of the product image giving the impression that the product image is missing. Talk about mess with your head. We have now found a way around this.

in my case go to shop url and delete all  address not start with https and every thing fine
all image is shown now