When zooming in from 3200% to 6400% or more, this line starts acting weird. The stroke should not be outside of the path line, but it seems like it's having a rendering issue or something. Seems like it might be a problem only when previewing on CPU. I switched to GPU preview and it's fine, but if I switch back it looks like the attachment
Please get in touch with us at any of the other support channels – https://helpx.adobe.com/support.html . Since this is not a generic issue that we can reproduce at our end, we will need someone to look into your machine to figure out what is going on here.
Ashutosh Chaturvedi | Sr. Quality Engineering Manager – Illustrator
second image (capture.png) is at 3200% (correct) and first image (capture2.png) is the incorrect one (6400%)