Additional features, settings, or issues not covered by specific Microsoft Teams categories
Hi M. Ichsan Hasibuan,
According to your description, do you mean that you cannot access the Planner created by the team member in Teams? If so, I suggest you open the plan in the Planner app to check if the plan does exist.
You can also click on the More Option(…) button next to the plan and choose Open in Microsoft Teams to check if you can open the plan in teams via Planner
If it doesn’t work, I suggest you try to remove the tab(do not check the Permanently delete this plan and all its tasks.. checkbox) then re-add it by Using an existing plan from this team and see if it helps
Best Regards,
Huni