To the OP.
I believe it must be a shear scaling problem with your hatches. Your printer is not near enough capable to reproduce the finesse you put into your drawings. I downloaded your file, and opened it with MacOS preview. I scaled it 800%. There still seems to be a really thin hair line viewed even with my Precision monitor 4K Dell (please see screenshot).
Your plotter does not know how to plot almost non existent lines, it has to do a software based rasterization within the limits of the hard wired dots per inch of the plotter mechanics (300dpi/600dpi/1200dpi etc).
When it's (the plotter) being hit with a precision too much for it, it comes to a limit and has to make a decision; To plot, or not to plot - that is the question.
Obviously it chose wrong.
AC25, Rhino6/7+Grasshopper, TwinMotion • Mac Pro 6,1 E5-1650v2-3,5GHz/128GB/eGPU:6800XT/11.6.5 • HP Z4/Xeon W-2195/256GB/RX6800XT/W10ProWS