If the initialize.sh test case stops the current unit the session is leaked.
since the cleanup.sh is not executed in that case.
Fix, call Test.Disconnect before stopCurrentUnit:

if( !Test.Connect() ) stopCurrentUnit();
else {
MonitorTriggeringSubscription.RevisedLifetimeCount = 100; // long timeout needed for this CU
if( !CreateSubscriptionHelper.Execute( { Subscription: MonitorTriggeringSubscription } ) ||
!SetTriggeringHelper.Execute( { SubscriptionId: MonitorTriggeringSubscription, TriggeringItemId: scalarItems[0], LinksToAdd: [scalarItems[0]], ServiceResult: new ExpectedAndAcceptedResults( [ StatusCode.BadMonitoredItemIdInvalid ] ) } ) )
{ Test.Disconnect(); stopCurrentUnit(); }
}