I’ve been wrestling with this for a few months, and am still no closer to a solution.
On my TV, some Amazon Prime offerings are very dark to the point of being unwatchable. It’s typically newer TV shows and films, although – weirdly – some of the new stuff is fine.
For example, the Rings of Power looks like it’s been shot in the dark. But Last One Laughing is fine.
This is a known issue, and various solutions have been put forward, such as changing the HDR settings. None of them work.
I even tried contacting Amazon customer service, who were clueless, offering helpful solutions such as increasing the brightness settings on the TV (for info, pumping up the brightness helps a bit, but not to the point that something is watchable).
I have a Sony Bravia TV which is a couple of years old, and there are no issues with content on any of the other streaming platforms.
Any ideas?