Hi @IBN
Have you tried cleaning Teams cache and browser cache for this user?
Would this issue persist if you login this account on another device?
Here is also a thread for your reference: Teams - problem creating lists from excel file
I suppose this may be caused by credentials.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.