I am seeing more of these complaints. HDMI cannot convert to DP via a simple converter cable. A DP to HDMI cable will not work. Those cables are made to go from Video card DP to Monitor HDMI port. Your options are as follows =
Video card HDMI out --> HDMI to HDMI cable --> HDMI to DP Active Converter --> DP to DP cable --> Monitor DP in
Video card HDMI out --> HDMI to DVI-D cable --> Monitor DVI-D in
Video card HDMI out --> HDMI to VGA Converter --> VGA to VGA cable --> Monitor VGA in