Google PR error

How to fix incorrect internal PR

[Namaste]

My hopepage is PR6
All the 2nd level pages are PR5
All the 3rd level pages were PR4

During an update a few months back, all the PR4s became PR3. 2 days later they recovered to PR4, but some got left behind. All level 3 pages I added after that update listed at PR4

How do I get pages that are left behind on PR3 back to PR4?

OR

Shall I create fresh pages for those keywords? and link from elsewhere?