
Maybe let’s start by checking where you are testing the agent.
Are you testing it directly in Copilot Studio, in the Test / Demo chat?
If so, during the test, do you actually see the SharePoint knowledge source listed in the sources used for the answer?
If you are testing the agent in Microsoft Teams, remember that you must save and publish the changes by clicking Publish in Copilot Studio; otherwise, Teams will still use the previously published version of the agent.