Can't build silk road trade posts - am i missing something?

[Choombi]

I am the glorious child maharaja of the Chola kingdom, in my great wisdom, I have decided to construct several trade posts On the portions of the silk road that pass through my realm.
Curiously, I have been told by my wise guardians that the places in which I wanted to build trade posts are in fact not part of the silk road, despite the fact the entire conversation happened in the "silk road inn for weary merchants"

All pictures taken in the same day, both territories have had the "silk road" modifier for a few months now uninterrupted.
So tell me wise adults, am I missing something here?

 

[yezhanquan]

Edit: There is a X next to the "On major trade route" condition. Smells like a bug.

 

[Dracko81]

Do you have horse lords active? There seems to be some issues with silk road showing up without the DLC.

 

[Choombi]

I do not, haven't bought it yet, that might be it.
Still, if the option is there at all, it must be a bug, no?

 

[Dracko81]

Yes, but it is also a known issue afaik. I've seen it mentioned a few times over the last couple of months.