When the Grasshopper window appears in the bottom left corner of the screen, upon launch, and is too close to, or overlaps the screen edge, the icons (i.e. Open, Save, Zoom, etc.) of the Canvas Toolbar weirdly rearrange themselves to overlap each other.
I’ve noticed the bug, since the early RhinoWIP 6 versions. It’s pretty hard to catch though and not really frequent. I don’t really get in the first place, why Grasshopper sometimes pops up so far to the left.
I’ve even tried, placing the window out of bounds and restarting Rhino, but that somehow doesn’t necessarily replicate the issue.
I’ve also never encountered it on the right side, but my Grasshopper window lives mainly in the left half of the screen.
When I move the window to the right the icons re-arrange and everything is fine.
I’m currently using version 6 (6.18.19260.10102, 2019-09-17) on High Sierra (10.13.6) on a MacBook Pro with an external display.