Just hooked up a new Ultra last night.
Whenever I hit play on any Max content it starts to load, screen goes black and then returns to Roku homepage.
The Ultra device itself is working fine and all other apps I’ve tested so far have no issue.
I signed out of the other Rokus from my Account manager and resigned in on Ultra, did not fix issue.
I know Max has issues from time to time but it’s working on my iPad.