Check with mobo support site for possible solution/bios update.
You could also ask them if a spectre/meltdown bios is available for your mobo/cpu.
If it displays normally in the OS, then, as Goodplay pointed out, it's a motherboard BIOS issue. If it does continue to display garbage in the OS, then it's a defective card.
Did you get any further. I have a Gigabyte GA-880GA-UD3H. Unfortunately it is rather old and I have the latest bios update installed, yet still no joy. I have disabled the on-board graphics and set the initial display to PEG but still get the weird screen.
Today I checked a socket on another 1151v2 motherboard, everything is fine. This problem is due to the fact that the bios logo of the video card is embedded in the screen of the motherboard, that is, in this case there was an asrock board and the logo was - Asrock/Sapphire.