I've demonstrated it here with the Rectangle tool, but I believe it applies to all sketch tools. I believe it is a clue that the Feature Tree pane is reloaded at the same time; it might mean that the artifactGraph being recomputed is causing this.

Steps to reproduce

1. Equip the rectangle tool
2. type x = 3 or something in the code editor
3. quickly place the first point of the rectangle
4. watch the second point be canceled, an a startProfileAt placed

Video