Yes, I repeated your test and can confirm that it is not plotting the first point at 0°.
When I thought it started at 0°, I think I was influenced by using IDE 1.8.16, which does start at 0°, and also the Serial Monitor.
I've no Idea why it is doing this.
Looks fine apart from the anomaly in the centre!
This is because I was plotting right up to 360°, and then starting again at the next point with 0° - which is obviously the same value printed a second time.
Easily solved by only plotting from 0° to 359°.