I have 2 different Nest Mini, and whenever I cast from my Pixel 2 Google Podcasts App, the app itself will stop keeping track of the podcast while the Nest continues to play. This will happen usually within 5 minutes of playing. This never happens when playing music or anything else, just the Google Podcasts App. The app will think the podcast stopped playing and is no longer connected to the Nest.
We appreciate the update. Have you tried rebooting your phone? If so, it's best to contact Google Podcast support since it's only happening on the app. Let us know if you have other questions or concerns with your Google Nest devices otherwise, we'll lock the thread after 24 hours.