This KB discusses some troubleshooting around response messages. There may be an instance wherein an Agent using Agent Chat via Agent Workspace experiences the following symptoms:
This could mean there is a discrepancy in the configuration of the Response Template Snippet [sn_templated_snip_note_template] and either the Agent and/or End User initiating the chat.
Please find the missing/expected snippet(s) and verify the condition builder values versus the users engaged in the chat. If the condition is failing, the snippets will not appear for the agent.