CivUP 2.3, GEM 1.12 Liberated into war

[Drakir89]

So I just liberated a city state captured by Mongolia, but it was allied with Siam (also at war with them) so it declares war on me and eats the unit I captured the city with.

Edit: after making peace with Siam they became my allies instead.

 

[Ahriman]

IIRC this is a vanilla issue that GEM can't really change.