Hdcp or high definition copy protection encrypts the video and audio streams between the source(blu-ray), repeaters (av receiver) and sink (monitors), normally a typical blu-ray player supports 1 encryption key from the sink, so for your case your blu ray player (source) checks the splitter (repeaters) what monitors (sink)are connected to it, for 2 monitors you need a source that supports 2 encryption key if your device supports only 1 key it will block the hdmi output. The number Hdcp key supported by a source is normally not documented in the specs. Just for your information a nvidia and amd videocard supports 16 keys or 16 sinks, the maximum of hdcp 1.0 is 128 keys. Hdcp 2.0 with hdmi 2.0 is another story