This is the problem:
I have a MainApp that contains an HelperApp. The Helper app is used for the login items so i need to differentiate MainApp and HelperApp bundle IDs.
I
You could try deleting your helper app, then adding it again this way: in Xcode go to file, add new files to "Your project", and import your helper app. Then, make sure they both have valid provisioning profiles for distribution.