Checking Windows HDR support in Plex player

PMP absolutely does not passthrough HDR10 metadata to the OS and then in turn passthrough to a HDR capable display. PMP will tonemap HDR10 content to SDR. Windows 10 will send that out as a HDR10 signal to the display hence AVR/displays reporting a HDR signal.

Again, there is no support for HDR10 passthrough from any version of PMP on any OS platform.