Roku says 3500x is supported by Roku. I've watched HBO max on the 3500x streaming stick. You have to start the app several times. It has to load piece by piece. First the most recent movie has to appear, then it goes back to home. Start again until the rest of the in screens appear. Once in all the screens appear (list if movies, continue to watching, my lists, etc.) You can start watching. It takes several attempts (it once took me 15).