When you take over a city with a wonder under construction, it cancels and gives the AI a chance to build it elsewhere. I get it if the wonder is not yet built you should have the ability to still build it, but in reality there's always some derelict unit somewhere with no ability to create a new territory just waiting to die in your borders, and no one gets the wonder.

Wow, it does?  Is that recent?  I always thought taking over wonder construction meant you get to keep it (admittedly I haven't done this very much)!

Yeah, it's new in the latest update, same with religious monuments. I definitely feel it was an attempt to prevent being over your cap of religious monuments, as in the ancient error the AI just keeps restarting the religious monument in the next city and you end up with one in every city. It makes sense, but it seems if the AI still has a "chance" of restarting a new city it gives them the ability to restart the claimed wonder there, even if there is no territory on your continent to claim or their only remaining unit is a pentekonter.

I liked that the contract to build was done and you earned that. Bring it back! If the religion monument has an issue that's fine. But not wonders