I just tried two times in a game to "steal" the opponents site with secret catacombs. It didn't get the influence score over. It got 0 instead of 6. It should have gotten 4 from the site opposite and two from master engineer.
I think the problem may be the secret catacombs when master engineer is in place. I think it is related to this topic, yet it is not totally the same:
This is not fixed yet on our side, that's why I'm not sure yet if it will be available in the next update And yes, this is linked to master engineer. There might be some other memories similar to master engineer which trigger the bug as well.