Hi Chris M,
I found this thread while researching the same topic. Is it OK to run this SE2717H monitor at 75Hz using my Nvidia GTX1070? When I use Windows to set the monitor to 75Hz (attached image), I get the same message on the monitor control panel as the above user: "Resolution: 1920x1080,75Hz Maximum: 1920x1080,60Hz". I am connected via HDMI. The manual further confused me because I see 1920x1080, 75Hz listed as the maximum preset resolution, but the maximum preset display mode shows "VESA, 1920x1080, 60Hz". Is 75Hz only allowed with FreeSync? I just want to make sure it is OK to have windows set at 75Hz with this monitor and Nvidia card even though the monitor itself is telling me that's above the maximum?
First, it should not read "Generic PNP Monitor". You need to install the SE2717H driver so SE2717H appears in the Device Manager. Second, the SE2717H supports AMD FreeSync technology 48-75Hz using HDMI, see page 10. The manual never states Nvidia and 75Hz. The SE2717H sales page never mentions Nvidia. It specifically states, "Adaptive-Sync Technology AMD FreeSync". My guess is trying 75Hz off of the Nvidia HDMI could cause unforeseen issues so you should back it down to 60Hz.
Try troubleshooting to check if your HDMI cord is directly connected to both sides. I had an HDMI going from the monitor to a DisplayPort adapter and it did not let me use 75Hz off of my 1660.