Can't direct AI vassal research?

[Outlandish]

I had Elizabeth as a capitulated vassal today, and I wanted her to research Scientific Method. It was in the list of her available researches. She was currently starting Liberalism.

I already had Lib, and was going to trade it to her with something else for Method. When I asked her to switch, I got the usual response of "We'll switch right away". However, she didn't switch. I tried again a couple turns later, she never actually switched and eventually self-teched Lib and messed up my planned Communism switch.

Is Lib a special case or what is there that can cause the AI to not change researches? First time I've ever seen this happen.

 

[lymond]

I've never seen that happen either. However, Lib enables the Free Religion civic which is Lizzie's favorite civic, so my guess is it has something to do with that. Apparently, AIs will focus on fave civic tech regardless of their master's direction. I've just not run across it before.

 

[ArchGhost]

I run into weird bugs in the diplo screen from time to time, like not being able to trade gold (click registers but does nothing) or unable to offer techs for trade. I think it it might be something related to some Python script bugging out. Restarting entire program and reloading lastest autosave has fixed it for me.