UserDefaults.standard was cleared and app UUDI is also changed when I update new version from app store

Facing issue of NSUserDefaults data got cleared on update new version from app store. so all data of user got cleared and user have to login again. I was having app in store with version 1.1.3 and then we have uploaded new version to store with version 1.1.4 but when user download app from store their data was cleared from UserDefaults.so this is big issue in update. need to help. is that apple updated any process on update. Question How Apple change version build in device when we update app from app store. is it uninstall old build and install new build ? Or it is install new version on old version ? Should UserDefaults.standard will delete on update ? Updating Provisioning profile from manual to automatically cause issue on UserDefaults.standard Like UserDefaults got cleared and uuid will change ? Do we have anythings that we can identify specific user as uniq user ? What is better solution to store login data into SQLite store or in UserDefaults as model ? Will appreciate for your help. this is very big issue and login again on update will make app user more effect