Good day PGN,
That does sound very odd.
I mean of course it can happen that a graphics card will mail-function, but this is a new one for me …
It sounds like the Graphics Card does not get enough power to operate. Your PSU should have about 48 Amp. available on the 12Volt rail. Graphics card will take 280Watt in full load, your cpu about 100Watt in full load and your mainboard could also take about 100Watt, HDD about 15Watt / SSD about 10 Watt. That would be about 500Watt or 42Amp. If you have a some power hungry External USB devices connected, that could become a bit tight. I am not saying it cannot work, but if at all possible, perhaps worth a try to test the card in a different system or test a different PSU in your system.
Did you also update the BIOS of the mainboard, this perhaps sounds a bit strange, but does often help a lot to make the system run more stable.