Test items are skipped (or not) based on declarations in tests class, using manifest, or @bug/flaky/missing_feature decorators.
You can force a disabled test to execute using the -F option, e.g.
./run.sh MY_SCENARIO -F tests/feature.py::Test_Feature -F tests/feature.py::Test_FeatureEdgeCase
A common use-case is if a feature covered by a test is currently in progress for your library. Once progress is complete, follow the enable-test.md doc to enable the test in CI.