Remote Access Permission

Hi there
I have a WD My Book Live Duo and set up the Remote Access.
Unfortunately I don’t quite understand the permissions settings.

Following situation:
I created a User on the MBL.
I created a Share on the MBL.
I granted that User read/write permissions on that share.
I created a Web Access Account linked to that user.
Locally I can do whatever I want on that share
Remotely I only have Read Rights. Meaning I can’t create folders or upload any files.

Can anyone tell me why this is not working??
Since I linked that Web Access Account to my local MBL Account IMO I should be able to manage my share, but I can’t.

Thanks in advance.