If you speak to Kahn and start off asking about the contract rather than negotiating the fee (picking last 2 dialogue options), you eventually become unable to accept the contract or negotiate the fee in that conversation.

If you then end dialogue and talk to Kahn again, you can ask about Oswald and the contract but still will not have the option to accept the contract.

Unfortunately didn't keep the save.

Same bug. Dialogue treats me as if I've accepted it, but it doesn't appear in the quest log and the next step (on the second floor of the quest's starting location) isn't available. Should I upload my save? How do I do that?

Greeting Px1Player,

 

This should be resolved for patch 1.1, please let me know if it is otherwise

 

Best,

 

-Caleb

I'm playing on 2.0 beta, but I find the bug is still not fixed. 

Just started a new playthrough on 2.1.0. The bug is still there. Quest doesn't show up in the questlog.

 

Cheers