https://github.com/ObeoNetwork/pepper/blob/main/backend/pepper-starter/src/main/java/pepper/starter/services/PepperMMLabelServiceDelegate.java#L34 should not extend DefaultLabelService, but only implements IDefaultLabelService, because it causes some conflicts when Pepper is used with others Sirius-based application like SysON (see eclipse-sirius/sirius-web#6468 for more details).
https://github.com/ObeoNetwork/pepper/blob/main/backend/pepper-starter/src/main/java/pepper/starter/services/PepperMMLabelServiceDelegate.java#L34 should not extend
DefaultLabelService, but only implementsIDefaultLabelService, because it causes some conflicts when Pepper is used with others Sirius-based application like SysON (see eclipse-sirius/sirius-web#6468 for more details).