The current version of LTSpice does not display traces properly if the .dc simulation has a negative increment.
This used to work in previous versions, but is currently broken (along with a few other "features).
Enclosed are 2 examples, 2SK246 Test Circuit -001.asc which is the one that should work but does not,
and 2SK246 Test Circuit -002.asc which works as it should.
Both examples are a curve tracer for an NJF.
Thank you,
Morty Tarr
MTarr Consulting LLC2SK246 Test Circuit -002.asc2SK246 Test Circuit -001.asc