End cities dissappear

I were playing on xbox on normal and then when i were building in nether i turned peaceful on when i were done i turn normal again and much time later when i defeated  ender dragon and went into end cities there weren t any endcities i were looking for these endcities over 6 hours and i haven t found any 

I also made the same world on creative in normal and defeated ender dragon and there were end cities so Peaceful Deletes Endcities WHYY Repair Thissss pls