Sierra (macOS 10.12.6) GPU rendering issues for Illustrator CC 2018
I recently upgraded to CC 2018, and I've been having issues with pathfinder as well as how paths are being displayed. Attached is a shot of what's occurring...this phenomenon not only happens in new edits since udpdating, but is showing up in files that did not display this way previously.
Joshua Moorhead shared this idea
Sarah Khan (Illustrator team) commented
Thank you for reporting the issue. Can you please share a file with which the issue is happening.