Yeah, may be issue is specific to certain models. Hope you get the update soon.My model number is 55UJ632T and it is on the latest version.
everything works just fine except hotstar.
Issue is not just GOT other movies and series too.
I had written to Hotstar support team and this is the reply i got
"We sincerely regret the inconvenience caused. We don't wish our users to face such issues on our platform while accessing their favorite content on our platform.
We have recently rolled out an app update for LG Web OS and this issue is resolved in this update. Request you to update the app to its latest version and retry. It should work fine.
Also, we have already highlighted the issue regarding audio language on LG TV to our concerned team and they are working on resolving it.
We would appreciate your patience, in the meantime."
hope it gets solved now.