Rich
Thanks Rich, After 2 hours messing around in WHMCS and Enhance found your "Golden" Tip.
Moving "temporary" to other client in Enhance and back to the original customer I could select the package!
Also editing in WHMCS the enhanceSubscriptionId to reflect to the correct package worked fine, suspend / unsuspend, it just started to work.
Up to the all other clients, that still are not in WHMCS with the correct packeges / domains.