Hi, I'm Bernard. I'm happy to help!
Kindly follow the steps provided by the AI answer. If the issue persists, I recommend changing the PC region to the US or the UK. Then, if the issue persists, create a new user and try to exit S mode using another account:
Method 1. Change the region to US or UK
Go to Settings > Time & Language > Change the "Country or region" to US or UK, then go to the Microsoft Store and switch out of S mode.
Method 2. Create a new admin user account, then switch out of S mode using the new account:
Go to Settings > Accounts > Other users > Add account
Follow the prompts to create an account.
Then go to Settings > Accounts > Other users > Select the account you created > Click "Change account type" then select "Administrator"
Restart the PC and log in to the new account, then try to switch out of S mode.
For reference: https://support.microsoft.com/en-us/windows/security/identity-signin/manage-user-accounts-in-windows