Quite a story, but in the end it worked out. After arrival in T3 I went up to departure level and eventually found the registration desk. THe entire team had disappeared for dinner. 10 minutes they slouched back and after another 5 minutes it was my turn. First the gentleman spent full 5 minutes looking at every page of my passport and then said he wouldn't register me as my passport wouldn't have an entry stamp. I showed him that it had. Then he spent anoter full 5 minutes searching me in the immigration records. Didn't find me. Turned to his colleagues, who searched as well until he realized that he had my first and family names mixed up. Finally found me. Back to the first guy. Did the entire procedure of putting my thumbs. Waited. Nothing happened. He said that the machine was broken and tried again. Thumbs, phone number, etc. Again, after a long wait, he declared that his system was broken and that I should try again next morning.

This morning I went to the same counter in departure hall, wanted to do it before immigration so I could try if it worked at departure. Same guy. "Maybe it works today". I waited for the gentleman in front of me to finish, then approached the counter. But behind me about 15 people exclaimed that they were waiting as well. So I gave up, went over to the F/C Terminal, went through immigration with my passport, went to the registration office, and 3 minutes later it was done.

My obsession to have it done for a usage on this trip has cost me easily 30-40 minutes of wasted time. I only have myself to blame.