[TYPO3-mvc] repository update through commandController does not proceed

[Domi]

Hello,

I try to update my repository in a SendMailCommandController Taks.

The $this->myRepository->findAll() query worked as soon as I set the 
setRespectStoragePage to false.

But following does not work:

$this->myRepository->update($element)

What am I missing? I checked $element, its a existing object but the 
database update does not happen, even that no error occurs.

Thanks for any enlightening.

Regards,

Dominic