TV brighter?

I have the following problem, my TV has 4K only my PS4 can't play 4K (since I do not have the pro). When I play PS4 my picture is pretty bright and you can see everything well, but if I go into Netflix on my TV from the Smart menu, then the picture is really dark. On Netflix on my PS4 but pretty bright (only supports them only Full HD) and would like to get the most out of my 4K TV. Have a TV from TCL (return is not synonymous, have bought the Euronics before dumb answers come). I put the picture on Dynamic, because otherwise the picture is really quite dark (like Netflix in the Smart TV). What can you do now? Brightening brightness in the expert mode is also not great, because then the picture does not look brighter just weirder because everything is whiter. So hope you can get that way, otherwise I'll probably have to get the 4K Fire TV Stick soon, as no Amazon Prime preinstalled or available in the store.

Eco / power save mode off.

Switch off ambient / light sensor

Background lighting up

Did not find where you can turn off the ambient light sensor, eco mode is not on, have it set to brightness +. And the backlight is already at 100.