From discussion in the issue and general CI-with-containers practices:

• Use a fully supported Docker runtime — in CI, instead of Podman, try using Docker (or a Podman configuration that truly mimics Docker’s networking/port behavior) because Testcontainers expects “Docker-API compatible container runtime.”

• Add a retry / wait for readiness — before your tests attempt to connect, explicitly wait (poll) until the Oracle listener/service is up inside the container. This helps avoid race conditions where the test tries to connect too soon.

• Ensure correct service name / connection parameters — double-check that the JDBC URL used by your tests matches the service name as registered in Oracle XE inside the container (default container service name may differ under certain environments).

• As a fallback: consider using a lighter in-CI database alternative (e.g. H2, PostgreSQL, MySQL) for integration tests — unless you specifically need Oracle. This reduces CI-container complexity.