I also performed your advice, cleared app cache, rebooted being on latest firmware and still no Max app available in app store.

@ruben I'm using the service from Romania. This is very frustrating, I can access the app from everything else. Why would it be georestricted I cannot...

@Ruben I cannot find any HBO Max or Max in VIDAA App store on my Hisense 55U7KQ. Is it available worldwide or is country restricted app?