Respond on UI can't send multiple messages in a row

I couldn’t find this under Known Issues or on GitHub, so I might have been the first one to try this.

I’m creating a chatbot using the Chat UI Trigger, and AI Agent at its core, and my goal was to have every step that the Agent performed send a message to the chat. For this, I created a Loop that iterated through the “steps” output of the Run Agent action, and inside the loop, I add a “Respond on UI” action that sends the markdown text of the current step into the chat, with a small delay of 3 seconds in between.

I noticed that the loop performs correctly, but the Chat UI seems to be unable to send more than 1 message. The first one is typically something like “OK, I’ll process your request”, the second one is a tool piece, and the 3rd one is the final response. But the Chat UI gets stuck forever on the “OK, I’ll process your request”, even tho the flow moved past that correctly.

I tried telling the AI to summarize everything into a single step, but it doesn’t seem to want to do this. And seeing how AI Agents work in every platform out there, I think it shouldn’t – it is normal for AIs to respond twice, or even more times, as they think and work.

Could you review this? It seems to be exclusively a frontend issue.