Some users are experiencing issues with Firefox working with Virtual Classroom and Zoom. This problem makes it impossible, once the room has been created in the Virtual Classroom, to open the session in Zoom. Since the integration of AulaVirtual and Zoom by default, you need the browser to allow cross-site cookie tracking.
This is why Firefox doesn't work, as Firefox's standard Privacy & Security settings block all "Cross-Site Cookies in all windows".
To solve it, there are different alternatives, two of them changing the Firefox configuration, and the last one changed the Zoom activity configuration in your AulaVirtual:
1. In Firefox, customize cookie tracking in your Firefox settings by allowing cross-site tracking.
2. In Firefox in Privacy & Security / Cookies and site data, add as exceptions: https://zoom.us and https://applications.zoom.us
3. In AulaVirtual edit the Zoom activity and in the General configuration change the default start container to New window.
Chrome's default settings for cross-site cookies do not have this problem.