Does anyone have any advice on how to make the walk-away option work in dialogue?

I've tried right-clicking on the branch connection and setting the option, and I've see the connector turn red to acknowledge that. And I've tried setting it from the info screen by checking walk-away and choosing the topic.

Neither of them seem to work. Guidance would be welcome

Hmm... It's not so much broken as partly broken, it seems. The first time you tab out, it works as expected. The second time, it doesn't. Not sure thereafter.