Issue you may be having with Option 1 is that the flight is full and they have pulled certain booking code classes from the ability to swap seats. I have seen that happen. Flight may also be within 24hrs but not within three hrs of flight were they block the entire flight and seats resulting in the inability to move around.

Normally, I am able to move my seats under the first option multiple times.

On a side note you may be trying to book in a EC or premium seat too far out from departure (24 hrs for employees) and it is refusing to let you move.