Hi,
They are enrolled, but did not receive the email. I have resent it, but I'm not sure if they are checking emails at the weekend. They did receive the notification for the Zoom meeting, which was scheduled using the Canvas Zoom plug-in, so something is working.
We had the same problem on another course, and we had to send each student a link and password, so I guess if they haven't received the invitations we'll do the same again. Until that's sorted out, I can send materials through email or Zoom. For future online courses, we might stick to that approach and not use Canvas, rather than going through this again. Thanks for your help.