The `ReactiveInboundChannelAdapterTests.testTimeSupplierConsistency()` subscribes a bit later than `@InboundChannelAdapter` might have started to emit messages. * Add `autoStartup = "false"` to the `timeEndpoint` and start in the test only when `StepVerifier` is subscribed * Add `stop()` for both endpoints in the test configuration to avoid memory pollution with not processed messages in between tests