NVIDIA's Pascal generation Quadro professional graphics boards support HDR; However, the PNY mini-DisplayPort to HDMI adapter does not support HDR.  If your 4K monitor features DisplayPort or mini-DisplayPort connectivity, then disconnect the HDMI cable and adapter, and instead use a mini-DisplayPort cable (or a mini-DisplayPort to DisplayPort adapter and a DisplayPort cable) to connect the 4K monitor to your Quadro graphics board.