Make sure your students are using their University of Essex login credentials to Single Sign On to the Zoom session. They should choose the SSO option on their device. Webinars and Meetings scheduled by CTO require that participants are members of the Essex domain.
Ask the student to check their online timetable and make sure they are attending the correct teaching event and that they aren’t in a group on a different time or day.
You can also check the departmental timetable to make sure the teaching event has been scheduled correctly.