Without being able to see your return and your previous year's return, no one here can fully explain why things changed this year. You mentioned that you are having the maximum taxes withheld from your paychecks. Based on the withholding tables, if you have more than one job or multiple jobs for a shorter period of time, the total withholding may not keep up with the income, which may lead to you owing taxes.
For some possible explanations, take a look at the following TurboTax help article:
Why do I owe taxes?
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"