To reproduce, run the following on a Windows 11 machine with screen scale set to 150%.
Also fails on macOS Ventura 13.3.1.

$ gradle --continue --info -PFULL_TEST=true -PUSE_ROBOT=true cleanTest :systemTests:test --tests DualWindowTest

DualWindowTest > testTwoStages FAILED
    java.lang.AssertionError: Button 1 action not fired
        at org.junit.Assert.fail(Assert.java:89)
        at org.junit.Assert.assertTrue(Assert.java:42)
        at test.robot.javafx.stage.DualWindowTest.clickButton(DualWindowTest.java:148)
        at test.robot.javafx.stage.DualWindowTest.testTwoStages(DualWindowTest.java:161)