I first started milling my own boards about 3 years ago using a grbl CNC mill and everything worked great. The designs have been done in eagle cad with the PCB gcode ULP. I put it down for quite some time designing things here n there but not cutting boards. I just realized that PCB gcode is no longer generating proper cut paths for the bottom layer.
Even when opening up old projects that once had perfectly fine gcode files, are now being generated defunct.
I rolled eafle cad back from 9.6.2 to 9.2.0 with similar results. The top layer works and etxhes just fine. The version of PCB gcode ulp has been the same since I first downloaded it a few years ago.
This is on a linux in 18 machine.
Any ideas? Its extremely strange to me that the top work a but the bottom doesn't. This is consistent with a complex new design, old design, and a single test with just one IC on top and bottom.
I'm not sure what to do next.