Solution:

Follow the steps below to remove only the Webex cookie from Firefox:

1. Press the Alt + T keys on your keyboard, which opens the Tools dropdown menu, then select Settings.
2. In the left navigation bar of the window that appears, click on Privacy & Security.
3. Under section Cookies and Site Data click the Manage Data button.
4. In the Search: field, type Webex.com.
5. Select the cookie you would like to remove, then select Remove Selected.
   • Note: You can hold down the Ctrl key on your keyboard and click on multiple selections to remove multiple cookies.
6. Click the Close button.
7. Exit all open instances of Firefox for the changes to take effect.