Help with Fields

I’m hoping you might be able to help with a slight issue I’m having when it comes to ‘fields’.

You can see below that there are 4 different fields to be completed, I have only input three which you can see in the second image below. Account Manager is not something that I have input and confused why it’s showing!

Is there anything you can do to suggest how to get rid of it / fix it?

Br

Greg