Edge NOT issue

[klayoutmatthias]

The following issue is seen on the attached layout file with this DRC script:

report("test")

l9 = input(9, 0)
l10 = input(10, 0)
l8 = input(8, 0) & l10

l0 = l8.edges
l0.output("0")
l0b = l9.not(l8)
l0b.output("0b")
l1 = l0.not(l0b)
l1.output("1")

The output of "1" is lacking a part of the edges (the "L" connected edges should be "U" in fact):

edge_not.gds.gz