Hopefully this is new information I did not see any reference to the issue.
I for the first time was posting to Vimeo but was unhappy with the results it looked dull compared to playing it on my computer very much the opposite of youtube which has it's own issues. After trying to figure what I was doing wrong I stumbled upon the fact Nvidia cards on PCs have a setting to change dynamic range. You can set dynamic range from Full (0-255) or Limited (16-235). This setting has no effect in my editor or you tube but makes a huge difference in Vimeo. It seems the default is 16-235 but changing it to 0-255 it makes my videos look as intended. I did check watching thru my Roku on TV and it is fine. This leaves me confused as I'm not sure how to react to this. Is this strictly a Nvidia issue? Have I been living under a rock unaware?
It also made me realize why I did not like some peoples color settings in Vimeo it wasn't them it was me lol.