Not working means when you click on the HBO Max app you see 3 dots for 5 seconds then goes back to the main screen. Also noted that HBO Max app works on my older generation iTV in the bedroom. HBO Max also works on my iPhone 12 (ios 15.4). Also noticed that in "Settings" that the HBO Max app is not longer listed as an app on the iTV.
Oddly enough, the video is visible when streaming a YouTube (not YouTube TV) video. This problem occurs when using both Chrome and Safari. I have restarted all devices, and all have been updated. The standard Apple AirPlay support pages offer no solution. No one ever replied with a solution to the post describing the same problem with Hulu in 2020.
For more info, go to Do I already have access to Max? Apple device: Try removing your TV provider from your iOS or tvOS settings: iPhone or iPad: Go to Settings > TV Provider. Under Allow TV provider to access, turn off Max. Apple TV: Go to Settings > Users and Accounts > TV Provider. Under Allow TV provider to access, turn off Max.