
Hi Jason,
Good day to you!
I hope you are doing well. Thanks for reaching out to our Microsoft Community Forum. We will be happy to help you.
I understand the inconvenience you are experiencing. According to the error message, the issue may be caused by your permissions to the root SharePoint site collection. To verify this, you can open the Private browser window and try accessing the root site "https://yourtenantname.sharepoint.com". Alternatively, you can visit www.office.com, click the SharePoint icon from the left sidebar or the search box, edit the current URL, and remove the part "/_layouts/…" to access the root site.
- If you are unable to access the root site, in which case you will need to contact your tenant admin (or IT team whose account has the Global admin role) to grant you access. Later, please check again.
- If you can access the root site, I recommend you reset SharePoint for iOS and then check again. Go to System Settings, scroll through your apps, select the SharePoint app, enable the "Clear Account Settings" option, then quit and restart the SharePoint app. Check to see if the problem occurs
If the problem persists after checking the above points, it would be better to check your tenant environment and your account at the backend for further troubleshooting. In this case, I suggest raising a support ticket from the Microsft 365 admin center, where the related team will have the correct channel and resources to collect the necessary background logs and check the environment remotely. You can contact your tenant admin or IT team and ask them to create a support ticket with Microsoft Support directly by following the steps from this link: Get support - Microsoft 365 admin | Microsoft Learn
Appreciate your understanding and patience.
Hope you having a nice day.
Sincerely,
George| Microsoft Community Moderator