An MSI 970 gaming + FX 8350 + RX 470 4GB with a Samsung monitor that supported Freesync over HDMI, was my main setup back before Ryzen came out. Polaris and Freesync breathed new life into FX at the time. Which makes me think that old 590 is probably a ragged out mining slave.
It might be worth testing in another system if you will get hit with a restocking fee or something. If it was covered by the hassle free, I'd send it back untested. Newegg has an open box ASRock 6700xt for $240 and a couple of 6750s for $280.
Also, my bad, it was the XFX 6600 I used in the FX setup.
https://www.3dmark.com/nr/684355