I had read or heard that puppet cities were not controlled by the human and they just provide benefits like gold and research but you can't control what they build. Pretty much by accident I was in the Economic Overview screen and clicked on one of the puppet cities. It actually opened the build queue for that city and I was able to change what the city builds. It was great for stopping the city from building useless buildings that increased costs. After the first couple of culture building, I switch the cities to building wealth and research and it worked.

anyone aware of this? is it a bug?

Don't have the game yet so cannot confirm. Honestly not surprised though, there was a similar bug in Alpha Centauri that even worked for enemy cities.

If that's true it has to be a bug. It's a defining characteristic of puppet states that you can't control their production.

Yeah, after analyzing this more it has to be buggy. I have quite a few puppets as India, who needs them more than anyone. All the puppets want to build barracks which is just plain bizarre. I realized after quite some time - as tile yields are not second nature for me yet - that this stupid puppets were not even building workboats for all the seafood resources they had. Anyway, I was able to get them to build workboats and whatever buildings I wanted.

As for wealth and research, I can only get them to build it for one turn before they switch back to a barrack or whatever.

If you want to change it, you're supposed to annex them. Has to be a bug otherwise.