Are you using persistence? When you change a .items file all your Items get reset to uninitialized (i.e. NULL). If you use persistence with restoreOnStartup then your Items will be initialized to their most recently saved value.
The problem is probably because your alert rules only trigger when the Item changes from OFF to ON but when you change a .items file without restoreOnStartup the next time FensterAlertActiveHaustuer changes it will be changing from NULL to ON so the rule doesn’t trigger.
