Page orientation problem when converting pdf to PDF/a

Hi, I drag drop a pdf to the Choose a File to Convert pane in PDFCreator.
I then choose the PDF/A profile to convert the PDF to PDF/A.

The problem is the orientation with the resulting PDF/A.
If I set Orientation to Landscape for the profile the result is Landscape.
If I set Orientation to Portrait for the profile the result is Landscape.
If I set Orientation to Auto-Detect for the profile the result is Portrait.

How to set the orientation to Portrait?
The Auto-Detect-option sets the orientation to Portrait but it does not feel reliable.