Permalinks not working

I just upgraded to 2.11.9 from 2.5.5. On my index page, the permalinks work, but when I choose month or day, they don’t.

The comment form shows, but there’s no article.

journal.lisaviolet.com , my index page, they work.

But if you go to the month of August , they don’t start tp work until you get the entries that are also on the index page (through the 18th).

I’m lost.

Thanks for any pointers.