Hello,
Microsoft is discontinuing the Commercial Data Protection version of Copilot. They are instead replacing it with the Enterprise Data Protection version of Copilot which currently has far fewer features than the old version.
See this FAQ for more information: Frequently asked questions about Copilot | Microsoft Learn
The short of it is they are migrating to solution and many of the features are no longer available as they re-work them into the new solution. You can navigate here https://m365.cloud.microsoft/chat and web search still works along with limited document uploads.
Thank you,