This was the exact issue I was having but a couple of weeks ago now, it started working for me. I thought at first pluto had rolled out a new version of the app to fix it, but they did not. It's the same version. I did open a ticket with Pluto as well so maybe they fixed something on my account. I had assumed that maybe they had some issue with their authentication process on the back end and fixing it would fix it for everyone, but maybe not, or maybe the issue has re-occurred. I would open a ticket with Pluto on this. The main reason I came on the Roku boards first was just to see if this was something easy on my end that I could fix that anyone else was experiencing, but it really appears to purely be a Pluto app issue.