The widget does not appear
Almost always no API key saved — the widget hides itself rather than showing a broken chat. Check System Health. After that, check your display rules and whether a caching plugin is serving an old page.
It says it does not know something that is on my site
Use the retrieval tester to see which passages the question finds. If the right one is missing, the page probably was not indexed or was extracted badly. See Fix a bad answer.
Answers arrive all at once instead of streaming
Something between the server and the browser is buffering. The plugin sets the right headers, but some hosts and proxies need server-level configuration. The chat still works — it just feels slower.
Nothing is being indexed
Check that scheduled tasks are running on System Health. Sites with WP-Cron disabled need a real cron job.
The AI bill is higher than expected
Look at the Dashboard for token usage per model. The usual causes are a large model chosen for simple questions, a very high context depth, or no daily cap set.