Implement a new solution: Instead of static code blocks disabling logging, rollback slf4j-api, logback-classic, and logback-core to older versions. It's the addition of the rollback for slf4j-api that seems to restore logging.

src/test/java/ca/uhn/fhir/jpa/starter/ExampleServerR4IT.java

@@ -43,11 +43,6 @@ import static org.junit.jupiter.api.Assertions.assertNotNull;
 		// when running in a spring boot environment
 		"spring.main.allow-bean-definition-overriding=true" })
 class ExampleServerR4IT {
-
-	static {
-		System.setProperty("org.springframework.boot.logging.LoggingSystem", "none");
-	}
-
 	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(ExampleServerR4IT.class);
 	private IGenericClient ourClient;
 	private FhirContext ourCtx;