As what I suspect but no biggie. When we are ready do the live import, we will just recreate those categories. I wish there was an importer for Phorum to Xenforo. :/ Any plan to add an Phorum importer to Xenforo soon?There is no method for changing node types in XF.
As this is an import, I suspect they were set as forums in the source database, or phpBB, before importing into XF.