Additional assignment-related features and issues within Microsoft Teams for Education
Dear ANJU S KRISHNAN,
According to the screenshot, your account was added as a Student when the Class team was initially been created.
I would like to suggest you switch to the Teams tab and click the three dots(…) on the upper right of the team's pane, select Manage team, on the Members tab, you may check whether your account is listed below the Owners or Members and guests.
If your account is listed below the Members and guests, you may ask one of the existing Owners of the Class team to change your Role from Member to Owner. After that, you may be able to create assignments on the Assignments tab.
Per my tests, there may have some delay in the Teams desktop client, and you may log into Teams web app to check the updates. If it's acceptable, the most efficient way is to re-create the Team and add your account as the Teacher.
*Some screenshots for your reference:
Assignments tab for students:
Assignments tab for teachers:
As an Owner of the team, change Role for existing members:
Thanks for your patience. Stay safe and have a nice day~
Best Regards,
Hugo