ZorinOS GPU Issue

So yesterday I installed a 7870 XT (got a good deal from a friend, $100) into the gaming PC I built for my little brother. When I got to the desktop, I encountered heavy artifacting. So, with a bit of a struggle to see what I was doing, I managed to install a proprietary driver which fixed the artifacting. However, now there is no audio going across the HDMI cable and in the sound options there isn't even anything listed for HDMI. Any ideas?

Does ZorinOS even run on a recent enough kernel that would allow HDMI audio?

I have no clue man lmao. Only reason I used Zorin is because it's easy for my family to use. Do you have any better alternatives to suggest? I'm starting to not like Zorin quite a bit, due to many little issues.