When we had the old chromecast (without google tv), casting from our Android's Netflix app was a breeze, and never had an issue with autoplaying next episode.
We recently got the Chromecast with Google TV (4k), and its been quite troublesome to use. If we cast Netflix from our Android phones, next episode wouldn't play automatically. I checked my Netflix setting and toggled the "autoplay next episode" feature, and rebooted the new chromecast, which seemed to temporarily fix it for the night, but it stopped auto playing next episode again the next day. Is there another setting I've missed?
Thanks for reaching out and for being a step ahead of us. Let's check this further.
Quick question: is this also happening when streaming Netflix directly from Google TV? Please reinstall the Netflix app on your mobile phone. Using a different mobile device might also help. If the issue persists, factory reset your Chromecast with Google TV (4K). Here's a guide: How to factory reset your Chromecast.
Let me know how it goes.