Your english is fine . Some electricial devices can be damaged by being wired up wrong as you originally did . This doesn't really seem to explain your problem since the flag pole fixture seems to be turning on & off & the lamp post fixture isn't . I don't know if the sensor could be bleeding enough power through to keep the lamp post on ( which is close to it ) when it's supposed to be off . Wierd things happen . It would take a meter to check it . The only other possibility I can think of is the hot feed wire is somehow making contact with the post lamp black wire . I think I would try another sensor & make sure it was wired properly the first time .