Additional meeting and call-related features and issues within Microsoft Teams for Education
Hi JoseLealJoseLeal,
The color dots you see next to other people's profile indicates the user's current availability and status to other users.
App-configured presence states are based on user activity (Available, Away), Outlook calendar states (In a meeting), or Teams app states (In a call, Presenting).
So, for users who did not respond but the presence show as red dot, a possible reason is they have another meeting or appointment on their Outlook calendar or they are on a call or in another meeting currently. This also applies to users who accepted but was not present.
For more details, please see: User presence in Teams.
Best regards,
Jennifer