Paragraph styles can’t be renamed or deleted

I cannot rename or delete two paragraph styles on a keynote document that does not have collaborators. I’m trying to clean up the styles to create a theme. One of the styles I can’t edit is labeled ‘Free Form’ which seems to be the default name Keynote gives a style when a paragraph style is copy and pasted from another document. I’ve replaced all the fonts not being used in the document, and have been able to rename/delete other paragraph styles. I am able to redefine the settings of the styles, but not delete or rename them. What steps can I take to resolve this?