Help on email notifications for education plan

Hello, I am using Miro to conduct a research project and this involves quite a huge number of students. I would like to ask how come when people follows a comment thread on my board, which belong to education plan, they do not receive any notifications through email even though they subscribed to it? What I did was to sent them the invite link for them to edit my board, and they do have their own email accounts as well, but why do they not receive any email notifications? Also, since I am under student plan, I can only invite up to 10 team members. Is there any way to resolve this issue as this is crucial for my project, thanks!!