New Browser Tab Opening to Previous or Existing Session

Hi adamlob,
Thanks for reaching out to the Microsoft fabric Community.

You can try the following troubleshooting steps to help isolate the issue:
• Open Microsoft Fabric in an InPrivate/Incognito window and check whether the behavior persists.
• Try a different supported browser (such as Microsoft Edge or Google Chrome) to determine whether the issue is browser-specific.
• Clear the browser cache and cookies for the Fabric site, then sign in again.
• Temporarily disable any browser extensions to rule out extension-related interference.
• Check whether the same behavior occurs for other users in your organization.

Please let us know the results after trying these steps.
Thank you.