I wasn't kidding about the tone mapping comment. I was trying to offer a possible reason why this user is experiencing a dark picture with HDR if i understood him correctly.
It's a real problem on all TVs because most content is mastered between 1000 and 4000 nits and some games to 10,000 nits. Tone mapping attempts to take content mastered at 1000 nits, for example, and squeeze it down to what the set is capable of. In doing so, it's either retaining the brightness and clipping over a certain nit level resulting in a brighter picture or it will try to retain the detail at the expense of loosing brightness. You can't have both unless the TV is capable of reproducing the native signal. These are facts and not opinion.
As for streaming services, they don't have a "switch" that says, this is XYZ TV so send the content with XYZ tone mapping to give the best PQ. They are mostly sending content now, based on the 1000 nit level, i believe, which is why a set with 1000 nit capability will be able to render the content "better" than a set with less capability.
Even with the new OLEDs, their peak luminance is in the range of 700 - 850 nits for the 2018 sets and all of them have an option that "throws away" the HDR10 meta data and performs tone mapping on the fly, frame by frame, similiar to HDR10+ in order to render the best PQ for the sets capabilities just to address this specific problem.
Just trying to help explain some of the issues that HDR presents to all TVs.