The test expects that the first request will go to the HTTP/2 server and the next will go to HTTP/3. But since the default config is to use Http3DiscoveryMode.ANY it can manage to send the first request with HTTP/3 instead.

Requests should be explicitly configured with Http3DiscoveryMode.ALT_SVC.

java.lang.AssertionError: Unexpected response body expected [apple] but found [orange]
at org.testng.Assert.fail(Assert.java:99)
at org.testng.Assert.failNotEquals(Assert.java:1037)
at org.testng.Assert.assertEqualsImpl(Assert.java:140)
at org.testng.Assert.assertEquals(Assert.java:122)
at org.testng.Assert.assertEquals(Assert.java:629)
at AltServiceUsageTest.testAltSvcMaxAgeExpiry(AltServiceUsageTest.java:412)