There’s definitely something whacky with Makuri Islands. These are some observations from free riding.
Avatar would usually ride in the centre of the lane. When approaching a single rider from behind my avatar swings out to the right maybe 2-3 rider widths away from the rider being passed. This almost always involves crossing the centreline with a huge gap between riders.
When being passed by a single rider the passing rider would appear to bump my avatar and then swing out over the centreline. This might be a latency issue but it was funny watching riders bump my avatar and then swing out after passing me.
I once passed a couple of stopped riders who were off the side of the road. My avatar still swung across the centreline to avoid them despite the riders being off the road.
Doing a race on NYC and group ride on Watopia I didn’t notice any of the wild swings. Perhaps because there were more riders around.