FluxBufferWhenTest > timedOutBuffersDontLeak() FAILED

[chemicL]

This test failed on CI on 3.4.x branch:

Test class reactor.core.publisher.FluxReplayTest

FluxBufferWhenTest > timedOutBuffersDontLeak() FAILED
    org.opentest4j.AssertionFailedError: [final GC collects all] 
    expected: 400L
     but was: 321L
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at reactor.core.publisher.FluxBufferWhenTest.timedOutBuffersDontLeak(FluxBufferWhenTest.java:167)