Hi,
You need to regenerate the permalinks, to do that go to “WordPress Dashboard > Settings > Permalinks” and click on the “Save changes” buttons without making any change.
I also have this problem and I use premium.
Fixed it. Can someone close this topic? I copied the product description and that copied the CSS picture to the other product.
Since my website is under maintenance, I will give gyazo pictures
When I first click on the product – https://gyazo.com/6d0084098354866e5e7f52ea4829f7e2
After I choose Small size – https://gyazo.com/3f9f4e49172f6e8caf05cefa0d65d000