Long HDMI cable doesn't work with my computer, but works with everything else. All ports of video card work

I have a 50' HDMI cable that does not work with my PC.

My graphics card is a Geforce GTX 970, and I'm on Windows 10.

When using the HDMI between and port on my graphics card and any monitor (Tested 3 monitors and 1 TV) I get no signal, or it will "blink" on, then off for about 10 seconds ad infinitum.

The HDMI works though. I've tested with an Xbox One, and another PC, and it works fine.

All the ports on the PC work, I've tested them with the monitors, and a different HDMI cable.

It's only the combination of my PC and this HDMI cable specifically. Any idea what gives?

Edit: As an additional detail, this was also happening before upgrading to windows 10, it was windows 8.1 prior.