Hello from my understanding the problem is with info from the feed and there is nothing that AntennaPod can do.
AntennaPod is only a podcast player and when you subscribe to a podcast (and download episodes) it’s like when on your browser you visit a site (youtube for instance) that is not working or report a link that to an expired website. Your browser can’t do anything about that.
As I see last episode was on February that means it’s still an active podcast and it’s likely the author / creator will correct it.