Been noticing a white line in what appears to be a transparent edge to the road texture.
At first I thought it was a blank texture with some white text on it (like a default blank texture), but when I rode Alpe du Zwift for the first time yesterday and got up to a high elevation it became clear that the white line was actually the jungle road at the lower elevation showing through a transparent edge in the road.
seems to be a graphical bug.