Step to reproduce:
1. Edit/Create a content Type
2. Set sort field to anything exept 'Location path'
3. Set sort order to 'DESC'
4. Save content type
5. Create & Publish content from this content type
6. Check the location sortField and sortOrder, (for example in the detail tab or in the REST location response). It should badly be set to 'PATH' & 'ASC'