Not your fault. The last DLC is not part of the Ultimate Edition. GOG sell it separately. Do you have the OST?

Outlaw Sectors isn't part of the Ultimate Edition though.

Did you buy Outlaw Sectors? Does GOG Connect work for you now?

EDIT:
Wow, while writing this message, 2 other people beat me to it. lol

I own the game and all the dlc it does not see it.

I own all the DLC, including Outlaws Sector which Steam doesn't consider part of the Ultimate Edition, but it still doesn't show up in GOG Connect for me.
As the others above, I bought the DLC separately, but Steam still lists Ultimate Edition as owned on the Store page.

Same boat. Own Ultimate Edition package. GOG doesn't detect it. Halp!!!

Same here. I own everything on Steam and it doesn't let me add it to my GOG library.

Same for me. Have the Ultimate Edition, doesn't work.

Yes, I have the same problem. Anyway to solve this? Perhaps the two versions btw Steam and GOG are different?

same problem here.

I sent in a support ticket and after 24 hours GOG still haven't gotten back to me yet.
great work gog you really make a name for yourself as a customer friendly company....

AFAIR, GOG will give these 20 games to you for free (if you own them on Steam, of course) - talking about "customer friendly". So keep your cool!

Btw, same problem here!

Как понимаю, данный вопрос не решится до окончания распродажи. Проблема в том, как я думаю, "SINS OF A SOLAR EMPIRE: REBELLION ULTIMATE EDITION" зарегистрирован в Steam как отдельная единица товара, а ни как сумма отдельных купленных единиц. Получается, что мы все в пролёте, кто поддерживал, играл и любил эту игру. Можно ещё раз выразить свою любовь - купив любимую игру на данной распродаже ;D

Same here. I have the game and all DLC's on Steam but Connect does not consider me eligible for the Ultimate Edition.

Would be interesting to know if anyone actually got it.

me too :(
I own the game with all DLCs except outlaw, which should be fine.

If Outlaw Sector doesn´t count, then Gog Connect is not working for me. Still saying i don't have the game... :S

I have been able to claim all the others i do own, though, so this is the only one giving me problems.