When hatching in anything other than World CCS. Create a hatch using ANSI 31 pattern. Create a second hatch with same pattern. Using Properties Painter, copy the attributes from the first hatch to the second hatch. The angle of the resulting pattern is set relative to World CCS, not the current CCS, so the angle of the hatch patterns does not match. Manually changing the angle of the hatch in the second pattern to '180' and then back to '0' fixes it.