Did you upgrade it in Galicia and move your capital there?
Moving your capital around costs nothing.
The intended challenge here seems to be to:
a) conquer an important province in the middle of the Tzim/Tremere warzone
b) hold it long enough to upgrade it twice
c) which is probably also expensive

Moving your capital is just fluff imo.

Yea.. I can see that.. only things with it are that
1) in that case the tooltip is wrong since it gives the name of your current capital rather then that fixed location
2) this is less a Tzim legacy (hold a specific historical location) and more a personal growth thing (like seeking Golgonda) so having it tied to a specific location is a tad weird as a challenge
3) The Tzim (and guessing all vamps) have an option to go for a harrmonious house - and going that route means that unless you're the Tzim who started with that domain (who gets an empire level thing) you basically have to start a war against your own fam. Which for painting the map is ok (sacrifices gotta be maid) but just seems a bit strange in this context

Mostly its the tooltip thing, sounds like that's just off and its talking about that fixed location

Well, unless you are from the same house as the original owner it is nor really an in-house war. Also, your harmony is not that much affected by the occasional war. It´s usually petty BS, rivalries, blackmail, murder attempts etc. that tank your unity. Boosting it also mainly involves many small gestures of good will and less really big moves. Just hand out useless artifacts, gently convert people, let them out of prison for free etc.
In the lore the Tzimisce are not exactly kind to each other - or to anybody, really. It would be perfectly in character to build your throne out of your uncle for not congratulating you to your birthday or whatever.