Just following up on this. I had been running CM 410 for a little bit along with GRBL 1.1; no issues so far. I did get the arc endpoint error that started this thread using a toolpath from Fusion 360. I found this thread, updated to Build 411, and it did solve the problem. I did notice though that in 411, I get some bugs when jogging the machine but I can’t reproduce the exact conditions that cause the problem. Sometimes when jogging with either my miniature wireless Bluetooth keypad or just by using the mouse, CM seems to hang where I can click the buttons in jogging screen, but I can’t get the machine to respond. Sometimes it takes a complete restart of CM in order to fix the issue.
@robgrz, I know that 411 isn’t probably ready for full public consumption yet, so just wanted to note the behavior. I wish I had more data to give. I will start paying attention to see if I can point to certain conditions.