Wisconsin does allow a taxpayer to itemize deductions while taking the federal standard deduction. However, you must enter your itemized deductions on the federal return in order for them to transfer over to the state return. There is no way to enter them on the state return.
Try to delete your state return and then add it back into your return. Once the information repopulates from the federal return, see if it will populate with the standard deduction for Wisconsin. If you have further problems, you may wish to contact a specialist that can work through that section of the return with you to see what is causing the issue.