Do I understand the tooltip wrong, or is this actually a bug?

[Dsingis]

I'm talking about the species right called "Residence"
We may choose between full citicenship, residence, slaves or undesireables.

Since I don't want xenos in my empire to have anything to say, even if I'm not a slaver I choose "Residence" for them.
The tooltip says:

Pops are free, but may not engage politically and the species cannot produce Leaders.

Exactly, what I want, they are tolerated to live here, but can't engage in politics, or leadership.

And yet, POPs with residence rights may still join/create political factions. Isn't that supposed to be impossible?

 

[TartarosHero]

Looking at the wiki. It seems it gives a modifier that lowers their political influence. My biggest use for it is that it stops bad species from crowding up my leader pool.

 

[SpectralShade]

Them political factions is them having an opinion. You can't remove that unless you turn them into mindless vegetables.
They might not be able to do much politically with that opinion, but they still have it and thus it affects their happiness depending on the state of the world.

 

[Sinister2202]

Have you hovered over their Pop? You should be able to see the value of their political power.