Blocks some ads on SoundCloud iOS. It usually blocks the first ad and if I am lucky the second, but only if I disconnect and reconnect to the WiFi. I am not sure why the ad blocking is inconsistent as it used to block all ads. I recently updated the SoundCloud app and upgraded to iOS 14 but I don’t know think that should affect how pi hole operates.
Use these tools to help you determine what should be blacklisted. It may be that you can't block ads on that app, if they have shifted to streaming the ads from the same domains as the content.