Observed once only in a personal job while doing extensive testiing, and on linux-aarch64.

Several tests failed, most in TimeoutException, some because they didn't get the expected ProtolException

[19:43:45.335] test H3ErrorHandlingTest.testConnectionCloseUnknownCryptoQUIC(): failure [40013ms]
java.util.concurrent.TimeoutException

[19:44:25.366] test H3ErrorHandlingTest.testConnectionCloseUnknownQUIC(): failure [40030ms]
java.util.concurrent.TimeoutException

[19:45:05.417] test H3ErrorHandlingTest.testDuplicatePushStream(): failure [40049ms]
java.util.concurrent.TimeoutException

Client exception [expected]: java.util.concurrent.ExecutionException: java.net.ConnectException: No response from peer for 30 seconds
[19:46:05.441] test H3ErrorHandlingTest.testInvalidCancelPushId(): failure [60023ms]
java.lang.AssertionError: Expected ProtocolException expected [true] but found [false]

Client exception [expected]: java.util.concurrent.ExecutionException: java.net.ConnectException: No response from peer for 30 seconds
[19:47:05.451] test H3ErrorHandlingTest.testInvalidGoAwayId(): failure [60009ms]
java.lang.AssertionError: Expected ProtocolException expected [true] but found [false]

Client exception [expected]: java.util.concurrent.ExecutionException: java.net.ConnectException: No response from peer for 30 seconds
[19:48:05.459] test H3ErrorHandlingTest.testInvalidGoAwaySequence(): failure [60007ms]
java.lang.AssertionError: Expected ProtocolException expected [true] but found [false]

Client exception [expected]: java.util.concurrent.ExecutionException: java.net.ConnectException: No response from peer for 30 seconds
[19:49:05.468] test H3ErrorHandlingTest.testInvalidPushPromiseId(): failure [60008ms]
java.lang.AssertionError: Expected ProtocolException expected [true] but found [false]

Client exception [expected]: java.util.concurrent.ExecutionException: java.net.ConnectException: No response from peer for 30 seconds
[19:50:05.478] test H3ErrorHandlingTest.testInvalidPushStreamId(): failure [60009ms]
java.lang.AssertionError: Expected ProtocolException expected [true] but found [false]

[19:50:45.488] test H3ErrorHandlingTest.testMalformedCancelPushFrame([B@7761f222, 0): failure [40008ms]
java.util.concurrent.TimeoutException
[19:51:02.429] Timeout signalled after 480 seconds

[19:51:26.694] test H3ErrorHandlingTest.testMalformedCancelPushFrame([B@5be728d, 1): failure [41205ms]