My documented family is from a region that shows 0%. How is that possible?

This can absolutely happen. Genetic clustering doesn't perfectly align with modern borders — nearby regions often share similar patterns. Your recent family history (birthplaces, migrations, marriages) may be more complex than it appears on paper. The model captures overall genetic similarity, not certificates for or against family stories. You can have strong genealogical ties to a location even if your DNA aligns more closely with a reference cluster from an adjacent region.