Gefen HDMI Detective Plus (EXT-HD-EDIDPN)

I used this to solve issues between a PC connected to a TV where the HDMI EDID handshake was being lost whenever the PC went to sleep. This solved it like a charm.

https://www.kvm-switches-online.com/ext-hd-edidpn.html

High Definition displays with HDMI inputs use EDID (Extended Display Identification Data) to ensure that a connected Hi-Def source sends compatible audio and video signals. When displays are switched away or disconnected and then reconnected, the EDID data can be lost, resulting in an incorrect signal or complete loss of audio and/or video.

The Gefen EXT-HD-EDIDPN HDMI EDID Detective Plus has been designed specifically to address this issue by recording the display EDID date and making it available to the Hi-Def source reliably and on a continuous basis. With DDC re-clocking technology, the reliability of HDCP handshaking is improved, ensuring that the Hi-Def source always receives the correct EDID. Using the Gefen Syner-G PC software or terminal emulation via USB, the installer can also manipulate/modify the EDID data to meet installation-specific requirements and resolve system-specific compatibility issues. The HDMI EDID Detective Plus has been designed for quick and easy programming and installation.