An update so far. I was able to update DOH-LUN separately as the reservation had been split. I was unable to select a seat for my wife and spent 45 minutes on the phone. It took them a total of 3 hours to fix the error in the reservation to select a seat. 1 seat became available on DFW-DOH and I upgraded my wife ticket. Again seat selection was not available. I used the chat feature this time and it took several requests for the agent to understand that I wanted to select a middle seat with an empty seat next to it (in hopes of another seat becoming available).

If no seats become available, should I go to the ticket counter or gate counter in DFW to inquiry about an upgrade?