Which podcasts? Which streaming company? Have you rebooted both your router and your Sonos?

I've tried rebooting,  reinstalling Iheart radio, Sonos, removing podcasts and adding them back, checking that I'm properly linked. It just started happening in earnest after fits and starts. Can't listen to any podcasts. Music is mostly OK. 

I tried unplugging the Sonos modem(?) as well as the speaker and Beam. 

So iHeart radio has podcasts? If music / radio stations from iHeart are working, and podcasts are not, it is much more likely to be an issue with iHeart’s servers. Have you contacted iHeart? Is there a specific podcast on iHeart Radio that can be tested? I used iHeart today to listen to a baseball game, but don’t think I’ve ever tried a podcast. 

It may be on Iheart's end. I've reached out to it too. It worked fine for years until this week.