Another "Comparison method violates its general contract!"

Another "Comparison method violates its general contract!"

I'm being asked to investigate a bug as part of my internship. A piece of
code is throwing java.lang.IllegalArgumentException: Comparison method
violates its general contract! A custom Comparator is comparing two custom
classes by looking at long member variables of said custom class return v1
> v2 ? -1 : v1 < v2 ? 1 : 0; The equals method for this custom class looks
at a String member variable of this custom class. We're having a hell of a
time reproducing the behavior. My knee-jerk reaction was to replace the
return statement in the custom Comparator with return v2.compareTo(v1);,
but my team is skeptical that this will address the problem. Can anyone
offer any insight?