I suggest starting by verifying the service health status of Microsoft Loop and related services in the Microsoft 365 admin center. Any reported issues or ongoing maintenance could potentially explain the "Failed to copy" error your pilot/test group is experiencing when attempting to copy Loop components or pages.
Next, review your organization's network connectivity, proxy, and firewall settings to ensure they are not blocking or interfering with the communication required for Loop to function properly. Additionally, have all affected users clear their browser cache and cookies, and ensure they are using a supported and up-to-date browser version for Loop.
Review the Loop service logs for any relevant error messages or clues that could help identify the root cause. Provide the session ID (0f450758-7893-407b-afe5-5e214b42edd1) and app version (20230328009.014) you mentioned to Microsoft Support, along with any error messages or logs.
Should the issue persist after these troubleshooting steps, don't hesitate to contact Microsoft Support. Their team can provide further guidance or escalate the matter if it is a wider service-related problem. Resolving the inability to copy Loop components or pages is crucial for ensuring productivity within your organization.