If I run a Earthworks report with a self drawn boundary I get a proper result.
But using a closed loop daylight line from the Isopach as boundary the program doesn't compute anything it shows 0, it spits out the report instantaneously. Some initial test on the boundary stops the report to compute the volumes.
It shows an area value but the triangulated area is zero.
Even if I macro explode and rejoin it, offset, edit the shape, change the elevation, change direction or export/reimport that line as DXF it still computes zero. Unclear why.