The integration with Karbon and TSheets requires an exact name match to establish the integration. Once established the name can be renamed in either system and still be linked.
However, while Karbon can handle the same name for a Client Groups, Organizations, and People, the integration with TSheets cannot support that. If you find Karbon asking you to re-generate the code linking the two systems together in the Time tab for a Client or Work item, it might be an indicator that you have the same name used for two distinctly different entities (e.g. Client Group and Organization).
To resolve, rename one of the entities (e.g. Client Group, Organization or Person) and re-generate the code in the Time tab linking the contacts between the two systems. If that doesn't resolve, go to: Settings > Connected Apps > TSheets > Manage and click Save and Sync to force the sync to occur again. If the problem still persists, please contact support via Help and Feedback with Karbon or emailing support at firstname.lastname@example.org