The following tests failed in the JDK18 CI:

javax/swing/JPopupMenu/4791569/bug4791569.java
javax/swing/JPopupMenu/4694797/bug4694797.java
javax/swing/JMenuItem/4839464/bug4839464.java
javax/swing/JMenuItem/4812431/bug4812431.java
javax/swing/JList/4908142/bug4908142.java
javax/swing/JList/4654916/bug4654916.java
javax/swing/JLabel/4822331/bug4822331.java
javax/swing/JInternalFrame/6438965/bug6438965.java
javax/swing/JInternalFrame/4732229/bug4732229.java
javax/swing/JInternalFrame/4302764/bug4302764.java
javax/swing/JFormattedTextField/4863121/bug4863121.java
javax/swing/JFormattedTextField/4741926/bug4741926.java
javax/swing/JEditorPane/5062649/bug5062649.java
javax/swing/JEditorPane/4712089/bug4712089.java
javax/swing/JEditorPane/4465905/bug4465905.java
javax/swing/JComboBox/5100422/bug5100422.java
javax/swing/JComboBox/4924758/bug4924758.java
javax/swing/JComboBox/4863833/bug4863833.java
javax/swing/JComboBox/4513773/EditableFocusTest.java
javax/swing/JCheckBox/6496144/bug6496144.java
javax/swing/JButton/4978949/bug4978949.java
javax/swing/InputVerifier/6480545/bug6480545.java
javax/swing/InputVerifier/4774166/bug4774166.java
javax/swing/DataTransfer/DnDAutoTests/Text/TextAutoTest.java
javax/swing/DataTransfer/DnDAutoTests/JTable/TableMetalAutoTest.java
javax/swing/DataTransfer/DnDAutoTests/JTable/TableMetalAutoTest_R.java
javax/swing/DataTransfer/4876520/bug4876520.java
javax/swing/BufferStrategyPaintManager/6354265/bug6354265.java
javax/swing/Autoscroller/4942216/bug4942216.java
javax/swing/AbstractButton/6298940/bug6298940.java
javax/accessibility/4986504/bug4986504.java
java/awt/Window/Grab/Test.java
java/awt/TextField/ZeroTimeActionEvent/ZeroTimeActionEvent.java
java/awt/TextComponent/DeselectionDuringDoSelectionNonVisibleTest/DeselectionDuringDoSelectionNonVisibleTest.html
java/awt/ScrollPane/RemoveChild/ScrollPaneRemoveAdd.html
java/awt/Multiscreen/RelativeBottom/RelativeBottom.java
java/awt/Modal/ZOrderTest6271792/ZOrderTest.java
java/awt/Modal/ParentExclusionTest/ParentExclusionTest.java
java/awt/Modal/NonModalWindowOpenBehindModalDialogTest/NonModalWindowOpenBehindModalDialogTest.html
java/awt/Modal/ModalDialogCannotBeMadeNonModalTest/ModalDialogCannotBeMadeNonModalTest.html
java/awt/Modal/FocusAndCoverOfModalDialogCanBeShiftedTest/FocusAndCoverOfModalDialogCanBeShiftedTest.html
java/awt/Modal/BlockedMouseInputTest/BlockedMouseInputTest3.html
java/awt/Modal/BlockedMouseInputTest/BlockedMouseInputTest2.html
java/awt/Modal/BlockedMouseInputTest/BlockedMouseInputTest.html
java/awt/MenuBar/ClickMenubarBlank/ClickMenubarBlank.java
java/awt/List/TriggerActionEventTest/TriggerActionEventTest.html
java/awt/List/PageUPSelectsItemsTest/PageUPSelectsItemsTest.html
java/awt/List/ListEnterExit/ListEnterExitTest.html
java/awt/List/ISCAfterRemoveAllTest/ISCAfterRemoveAllTest.html
java/awt/List/ActionEventWhenHitEnterTest/ActionEventWhenHitEnterTest.java
java/awt/LightweightComponent/LightweightDragTest/LightweightDragTest.html
java/awt/Graphics/ClippedCopyAreaTest/ClippedCopyAreaTest.java
java/awt/FullScreen/VramExaustionFSTest/VramExaustionFSTest.java
java/awt/Frame/DisabledParentOfToplevel/DisabledParentOfToplevel.java
java/awt/Focus/VetoableChangeListenerLoopTest/VetoableChangeListenerLoopTest.html
java/awt/Focus/UpFocusCycleTest/UpFocusCycleTest.html
java/awt/Focus/SortingFocusTraversalPolicy/RowToleranceTransitivityTest/RowToleranceTransitivityTest.html
java/awt/Focus/SetFocusableTest/SetFocusableTest.html
java/awt/Focus/SequencedLightweightRequestsTest/SequencedLightweightRequestsTest.html
java/awt/Focus/RestoreFocusInfiniteLoopTest/RestoreFocusInfiniteLoopTest.html
java/awt/Focus/RequestOnCompWithNullParent/RequestOnCompWithNullParent.java
java/awt/Focus/RequestOnCompWithNullParent/RequestOnCompWithNullParent_Barrier.java
java/awt/Focus/ModalDialogInFocusEventTest/ModalDialogInFocusEventTest.html
java/awt/Focus/LabelScrollbar/LabelScrollBarFocus.html
java/awt/Focus/KeyStrokeTest/KeyStrokeTest.html
java/awt/Focus/InitialFocusTest/InitialFocusTest.html
java/awt/Focus/InactiveWindowTest/InactiveFocusRace.html
java/awt/Focus/ForwardingFocusToProxyMotifTest/ForwardingFocusToProxyMotifTest.java
java/awt/Focus/FocusForRemovedComponentTest/FocusForRemovedComponentTest.html
java/awt/Focus/ExtraPropChangeNotifVetoingTest/ExtraPropChangeNotifVetoingTest.html
java/awt/Focus/DisposedWindow/DisposedWindow.java
java/awt/Focus/DisabledAutoTransfer/TestDisabledAutoTransferSwing.html
java/awt/Focus/ConsumedTabKey/ConsumedTabKeyTest.html
java/awt/Focus/ComponentLostFocusTest/ComponentLostFocusTest.java
java/awt/Focus/ClearMostRecentFocusOwnerTest/ClearMostRecentFocusOwnerTest.html
java/awt/Focus/AsyncUpFocusCycleTest/AsyncUpFocusCycleTest.html
java/awt/EventQueue/PushPopTest/PushPopTest.java
java/awt/event/MouseEvent/DragToLightweightTest/DragToLightweightTest.html
java/awt/event/KeyEvent/KeyTyped/Numpad1KeyTyped.java
java/awt/event/KeyEvent/KeyTyped/EscapeKeyTyped.html
java/awt/event/KeyEvent/KeyTyped/DeleteKeyTyped.html
java/awt/event/KeyEvent/KeyPressesOnDisabledComps/KeyPressesOnDisabledComps.java
java/awt/event/KeyEvent/ConsumeTest/ConsumeTest.java
java/awt/dnd/DragTriggerEventTest/DragTriggerEventTest.html
java/awt/dnd/AccessControlTest/AccessControlTest.sh
java/awt/Dialog/ModalShownFromNonEDTTest/ModalShownFromNonEDTTest.java
java/awt/Dialog/ModalDialogOnNonEdt/ModalDialogOnNonEdt.html
java/awt/Dialog/DialogAnotherThread/JaWSTest.java
java/awt/Component/VisibleHwInLwContTest/VisibleHwInLwContTest.java
java/awt/Component/DisablingLWDisabledHW/DisablingLWDisabledHW.java
java/awt/color/WrongBGRestoration/WrongBGRestoration.java
java/awt/Choice/ItemStateChangedRemoveTest/ItemStateChangedRemoveTest.java
java/awt/Choice/IconifyClosesChoice/IconifyClosesChoice.java
java/awt/Choice/ChoiceFreezeTest/ChoiceFreezeTest.html
java/awt/Choice/ChoiceDragEventsInside/ChoiceDragEventsInside.java
java/awt/Choice/ChoiceConsumeMouseEvents/ChoiceConsumeMouseEvents.html
java/awt/Choice/BlockedWin32Choice/BlockedWin32Choice.java
java/awt/Button/DoubleActionEventTest/DoubleActionEventTest.html

There are a variety of failure modes.