[1.2.3] AI's former capital vanishes in Exploration

[RaidandTrade]

Not sure what's going on here. I've rolled over to Exploration and am ready to go to war with Amina:

She has two cities: Qohayto and Koloe. It looks like she's elected to move her capital to Koloe and rename it Gao but... existing city vanishes as soon as we roll over to turn 2 leaving this:

Save file attached.

I tried a turn 1 DOW and attacked the city and rolled to turn 2 and same result. Is this a bug?

 

[dogus2000]

I experienced a similar issue in my game in 1.2.3 when transitioning into exploration, one of the AI civ adjacent to me appeared to lose cities