Hi Jim Utley
Sorry to hear you’re running into this! That’s understandably frustrating.
You can try uploading the files in smaller batches, instead of all at once and include your full request in the same message as the upload, rather than relying on follow-up prompts.
Also, when Copilot gives a response, using the Thumb Up/Down feedback option helps flag these issues to Microsoft so they can improve the experience over time. Just as a note, this is a public user-to-user forum, no one here have access to your account or backend systems, so we can only suggest workarounds or the path you can take.
I do really hope this will be improved in the future.