I can open HBOMAX, but when I select a movie to download it does not open. I get 3 dots that keep blinking.
Have you tried
Specifically the last 4 steps to override the user agent string the DVR browser is using?
Unfortunately, HBOMax only accepts subscribers with USA credit cards, so it is not possible for me to register for an account to test. Could you please send share your login credentials? Please email to firstname.lastname@example.org and reference this ticket.
I done all of these things and I can open HBOMAX, but when I select a movie to download all I get is the three dots that show the movie is trying to open, but it never opens.
Unless you or someone else is willing to share login credentials so I can have a look then there is not much I can do to see what HBOMax is doing to try and support it.