It's nice to have you here in the Community. I'm here to clarify why you're seeing a different sales tax center between the two clients.
QuickBooks has launched a feature known as Automated Sales Tax which is designed to automatically track sales taxes. Since the two interfaces look different, it sounds like one of them is on the Manual Sales Tax Center.
I'm including some articles with additional information on this, with the first article pertaining to the Manual Sales Tax Center and the others related to the Automated Sales Tax Center: