I think what you mean is that it is not possible to fix the tablet in Portrait mode. You have Autorotate function on, and the tablet will have the Home screen in Portrait orientation if you hold the tablet that way up. You then click the Quicksettings icon to fix the tablet in Portrait mode - the Portrait icon appears for a few seconds, then changes to the Landscape icon and the orientation changes to Landscape.
This has been a "feature" of the latest Lollipop update on the XZ Tablet, and one Sony person suggested it was imposed by Google. If this is the case, it is very disappointing - we should be complaining to Sony who can then bring to bear their weight behind requesting a change by Google. Individuals complaining directly to Google is a complete waste of time.
