Apple Podcast not recognizing a podcast subscription

I have a 2017 iMac. I subscribed to The Rest is History podcast about 4 months ago. In the last month Apple Podcast is not recognizing I am subscribed and is not letting me download anything. I can play it on the computer, but it won't let me download it onto my iPod.

I go to the podcast website and keep trying to re-connect but it's not working. They have no tech support at all.