Sorry, but I can't run a scenario on the Michigan Use Tax in the Online TurboTax product. I can only test it in the desktop product (CD/download), which also has the advantage of being able to enter/correct it in Forms Mode.
You can phone TurboTax Support, if you wish, and they can walk through the state interview with you to see what is happening.
You can use the form at the link below to schedule a call back, or it may provide a number. Hours are 5AM-9PM Pacific (8AM-12 Midnight Eastern) 7 days/week.
https://support.turbotax.intuit.com/contact
