sub-category showing up in wrong order in breadcrumbs

As you said, you’ve a category (parent one) named as Oregon and its sub-category ‘Southern’, therefore, Oregon / Southern is the correct output.

It seems others are in wrong order. If Oregon is parent for Willamette Valley and Central then the result should be:

  • Oregon / Central
  • Oregon / Willamette Valley

Consider what hierarchy you exactly have in the backend vs. what you exactly need.