Hi, I'm Bernard, a fellow Windows user. I'm happy to help!
This issue occurs when there is an account in settings, or there is a miscalibration with the system. To sort out the issue, kindly follow the steps below:
First, you need to check if you have a work or school account:
Open Settings> Click Accounts> Click Access work or school, then disconnect the account there, if no account or already disconnected, and if you have the same issue, follow the steps below:
Method 1. Reset Microsoft Store
Press Windows key + R, then type in:
wsreset
Then hit OK
Method 2. Check the time and date
There are countries that are not supported by the Microsoft Store. You may try to change it temporarily to the US or the UK.
Go to Settings > Language and Region > Change the "Country or Region" to UK or US.
Method 3. Remove any emails from settings
Press Windows key + i (Open settings) > Click Accounts> Click access work or school > Disconnect or remove the account there.
Method 4. Create a new user
Try to create a new user and switch out of S mode from there.
You may follow the steps provided below to create a new user: