Shulker box Color problem

when i change the color of shulker box its resets the shulker box its becaming a new shulker box items inside of the shulker box missing.  i serched my tools shulker box for 2 hours to find out if i put it somewhere than when i cant find it i desided to make new one i put a new name with anvil everything was ok than when i want it to dye it was no name and shulker box was empty..