You should use the "Delete a Form" tool to remove the 1099-MISC and then re-enter it correctly in the W-2 interview.
After deleting those forms, log out of the program. When you log back in, you use the Delete a Form tool to see if the 1099-MISC has been removed from the list of forms in your return. If it has, you can then re-enter it in the appropriate Business Income interview.
If the delete and re-enter process does not allow you to correct the problem, you may have to try Using Clear & Start Over in TurboTax Online
Why does this happen? Once you enter (or import or transfer) certain information, the program creates or updates forms and worksheets that use that information. In many cases, you cannot "change" that information in the interview process - in a manner of speaking, it has been "written in ink" on the forms. You have to delete the form and any associated worksheets in order to correct.