Removing the User’s profile from the Outlook App:
In both cases, the users account was removed from their Outlook before I tried to solve the password issues. In order to remove the user from the Outlook App:
Firstly, go onto Outlook. Along the top toolbar, on the left-hand side there is an 'Outlook' Tab.
Click this and go to preferences.
Once the preferences option has been selected, there is a menu that has various choices on. Here the 'Accounts' option needs to be selected.
Once the 'Accounts' option has been selected, a list of all the accounts that have been signed in on the Outlook app will appear.
At the bottom left of this list there are plus and minus signs. These do what they would suggest, the plus adds a new account to the Outlook App, the minus removes an account.
This screenshot shows no users listed (this is what it will look like once an account has been removed.) As you can see, the plus and minus sign are highlighted in the bottom left.
In both instances of the issue, the account was removed (passwords are removed later, so all account information is cleared before the fix can take place.).
Following this 'Quit' (right click the Outlook icon on the toolbar and select 'Quit') the Outlook app. Make sure it is not open during password deletion.