v1.0.51 remote control regressed for valid meta-repo workspace with personal Copilot seat

[warrentc3]

Describe the bug

After updating to Copilot CLI 1.0.51, remote control became effectively unusable in my normal workspace shape.

The workspace root is C:\git, which is a real git repository, but it is a meta-repo / submodule root rather than a clean 1:1 GitHub repo.

Important detail: my Copilot license is personal, not provided through an organization. I do have a personal GitHub organization for repo separation, but my Copilot seat is not org-assigned, so organization remote-control policy should not be the governing explanation for this case.

In 1.0.49, the same workspace shape could still create a repo-less remote session that was steerable.

In 1.0.51, the CLI still says remote is enabled and active, but then the remote exporter repeatedly fails with Mission Control 400 bad request responses and opens its circuit, which makes remote control effectively broken.

Affected version

GitHub Copilot CLI 1.0.51

Steps to reproduce the behavior

1. Use a workspace root that is a valid git repo but acts as a meta-repo / submodule root (in my case C:\git).
2. Start Copilot CLI in that workspace.
3. Enable remote control (or let it start enabled).
4. Observe startup logs and remote behavior.

Expected behavior

If remote control is enabled for the account, the session should remain remotely usable.

At minimum, this workspace shape should not present as:

• remote access enabled
• remote session active / steerable
• then repeated exporter failures with 400 bad request

If this topology is not supported, the CLI should say so explicitly at point of use.

Actual behavior

Current 1.0.51 log (process-1779362087380-76408.log) shows:

2026-05-21T11:14:48.121Z [INFO] Remote session access enabled
2026-05-21T11:14:48.126Z [INFO] Remote session export enabled: https://api.individual.githubcopilot.com/agents
2026-05-21T11:14:48.255Z [INFO] No GitHub repository detected — creating repo-less remote session
2026-05-21T11:14:48.389Z [WARNING] could not load remote agents, no GitHub remote found
2026-05-21T11:14:48.889Z [INFO] Remote session active (steerable): https://github.com/copilot/tasks/...

Then shortly after:

2026-05-21T11:15:10.292Z [WARNING] Failed to submit events to Mission Control session ...: 400 {"documentation_url":"https://docs.github.com/rest","message":"bad request"}
2026-05-21T11:15:10.292Z [WARNING] RemoteSessionExporter: failed to submit batch, re-queued 457 events and 0 command acks
...
2026-05-21T11:15:21.267Z [WARNING] RemoteSessionExporter: circuit opened after 5 consecutive failures

For comparison, the same workspace on 1.0.49 logged:

2026-05-20T10:37:13.299Z [INFO] Remote session export enabled: https://api.individual.githubcopilot.com/agents
2026-05-20T10:37:13.353Z [INFO] No GitHub repository detected — creating repo-less remote session
2026-05-20T10:37:13.903Z [INFO] RemoteSessionExporter: active with session ...
2026-05-20T10:37:13.903Z [INFO] Remote session active (steerable): https://github.com/copilot/tasks/...

Additional context

• This does not look like an org-policy denial for my account. My local logs show Remote session access enabled, not policy-disabled messaging.
• The docs currently say remote control requires a working directory containing a Git repository hosted on GitHub.com. My workspace is a real git repo, but it is not a simple 1:1 GitHub repo shape.
• The current failure mode is confusing because the CLI appears to enable remote successfully, then degrades later.

[warrentc3]

Related issue: #3442

This may be part of the same 1.0.51 remote-control regression cluster, but my case appears distinct in one important way:

• my Copilot seat is personal, not org-assigned
• local logs show Remote session access enabled
• the session is created as repo-less and even reported as steerable
• the failure happens later when the remote exporter starts returning Mission Control 400 bad request and opens its circuit

So if #3442 is the policy/error-message surface, this issue may be the repo-topology / repo-less remote-session failure surface of the same broader regression.