Independent Power halfway disappeared the same turn I became suzerain and it was dispersed

[MutilationWave]

Napoleon was hitting an independent power between our empires pretty hard from the beginning of exploration age. I was their suzerain in antiquity. On the second turn when they appeared I did befriend independent power and boosted it. I sent a unit by to watch because it was going to be close.

So the same turn I was set to become suzerain, Napoleon killed their final unit and dispersed them. I am their suzerain, their city name still shows on the map but the city is gone. They retain ownership of their tiles except for the tile their city was on. Even though I'm suzerain visually and in the list, I can't move units into these tiles.

This is probably pretty rare to encounter. I'm going to reload the age and boost twice because I really want their camels and position as a Napoleon buffer.

 

[MutilationWave]

I've got an update to this if anyone is interested. I restarted exploration three times.

On the first go I boosted the independent power a second time towards conversion, so it would switch over one turn earlier. Napoleon again dispersed it on the turn I would have become suzerain.

Second restart I boosted it three times at the beginning of the age. I would have become suzerain 3-4 turns earlier. Napoleon again dispersed it on the turn I would have become suzerain.

Third restart I was like I just want to play the damn game and ignored the independent power. I'm now nine turns further in than the original save and Napoleon hasn't touched the independent power.

I originally thought this would be a pretty unique situation, but there's something behind the scenes making Napoleon do this crap. So other people might see this. It's frustrating.

 

[Tilarium]

This is happening to me, only nobody is attacking them. Has to be a bug. The same turn I become the Suzerain their city vanishes but the tiles are still there. I can click on them to interact, but everything is greyed out except for declare war. Very not cool!

EDIT: After some light testing, I think (at least in my case) the problem is because the city itself is on a resource tile. It looks like it was a bug that they fixed in 1.1.0 but has resurfaced in 1.1.1.