Please go back to the My Info or Personal Info section and edit your spouse. On the next screen where you enter your spouse's name, date of birth, etc., scroll down until you see "3. A few other things we need to know".
Is the answer for the first question "Someone else can claim my spouse as a dependent on their tax return. Learn more" "yes" or "no"? You want it to be "no".
If this is not the problem, you may have to delete your spouse and re-add him/her. To do that please do the following:
1. Make sure that you have copies of all your spouse's forms and income documents.
2. Go to the Personal Info Summary where you, your spouse, and any dependents are listed.
3. Edit your filing status to Single. (this should remove your spouse)
4. Go back and add your spouse.
5. Go back and add any income forms that were deleted when you deleting the spouse.