Unable to detect intent from custom action


I’m using Rasa 2.0 with a custom action to send a message with buttons as follows:

lst.append({'title': title,'payload':'/example{{"item":"{}"}}'.format(item)})

Then, I’ve defined in my domain.yml the item entity, item slot for future purposes and example intent and include example intent in my happy path story. However, rasa core is unable to detect this intent properly. The only way that I get it works is by removing item entity from domain.yml (with de rasa core warning)

I’m doing something wrong or misunderstanding the purposes of intents, entities and slots?

Thanks in advanced,