Q: My podcast artwork is not refreshing

The images that appear for subscribers are nothing to do with the image which appears in the Store - when subscribing you see the image actually embedded in the media file, if there is one - you have such an image in your first episode but not your second.

As to the image in the iTunes Store, this is cached by the Store, and if you change the image without changing the filename the Store has no way of knowing that it's a new image and may well not update. Even if it does, it usually takes quite some days before the new image appears. You could try refreshing your feed at Podcasts Connect - this is a new facility and I don't know whether it will make any difference.

The only solution if you can't change the file name for the artwork is to move off soundcloud.

It is not a good platform for podcasters - you need to pick one where you can change your file name and even your show title if you want.

Look for a new podcast provider.

https://itunespartner.apple.com/en/podcasts/partnersearch

The link above is to the iTunes Podcast Partner page.  As you will see soundcloud gives you very few of the options Apple considers important.

Rob W