The following test fails most of the time (about 75% of the time I run it) on my Ubuntu 20.04 VM system (VirtualBox guest running in a Windows Host)

InitialSizeTest > testInitialSize FAILED
    java.lang.AssertionError: Stage height expected:<200.0> but was:<208.0>
        at org.junit.Assert.fail(Assert.java:89)
        at org.junit.Assert.failNotEquals(Assert.java:835)
        at org.junit.Assert.assertEquals(Assert.java:555)
        at test.javafx.stage.InitialSizeTest.testInitialSize(InitialSizeTest.java:79)