Load https://dglazkov.github.io/botg/ and drag the points on the purple line. Note how the dashes on the center, vertical gray line move around.
This feels like we use the wrong dash offset when we're only painting a subset of the path.
<rdar://problem/88159306>
This is a bug in an underlying graphics framework.
We believe that this bug has been fixed in: macOS Ventura Beta 1 (and newer) iOS 16.0 Beta 1.