duplicate post category after website migration

I recently migrated the main blog of a multisite to the subsite of a different multisite. When this was completed, I noticed that there was a duplicate post category on the subsite in which new autoblog content assigned to the category was propagating — I can see this when I view the post archive widget hierarchy, there is a duplicate of the "Strategies to End Homelessness" category. It appears that all the former autoblog content in this category is assigned to one of the duplicates, and all the newly generated autoblog content is in the other duplicate category. When I went to edit the post categories, figuring I would just merge the content and delete one of the duplicates, I saw that the duplicate was not listed there… can't find the duplicate anywhere, except in the list that shows up when you want to assign a specific post to a category; that is, you can see that there are duplicate post categories when editing the assignment of a post category, but not when editing the post categories… VERY strange. Need some help merging the categories! The subsite located at https://unitedresourceconnection.org/cincinnati. The domain has been mapped to https://cincinnati.unitedresourceconnection.org to maintain the google analytics from the old site, so don't let that confuse you, e.g., the unitedresourceconnection multisite has directory structure not a subdomain structure. Support access has been activated.