Import issues

I have tried a couple of import plugins with this theme and seem to be hitting the same issue with both of them.

Posts import from the csv correctly and if categories are selected and the category name entered, end up in the right place.

None of the posts have a next/previous article link at the bottom of them

if I create a post manually in the same category, it will show the first bulk uploaded post and I can navigate back and forth between the manually entered post and the first of the bulk uploaded posts but none others are displayed.

If I display the category, all posts are visible and can be accessed individually.

I have tried removing the category and reapplying it, bulk deleting the posts and reuploading with no category, then manually assigning the correct category but nothing works.

If I want to navigate from one post to another I have to enter each post manually.