Pixelated Line Tracking Along with Avatar?

Does anyone know why I have a pixelated line tracking along with my avatar? Almost like a permanent fence that’s stuck in front or behind my rider (or anyone else I watch). I’ve tried lowering the graphic settings, but still no luck.

Sounds like this: Black ‘Refracting’ line on the road

Yep that’s my exact issue. So from what I can gather from the other thread…I’m pretty much in the minority with my older Mac and the issue won’t be going away anytime soon.