I don't know if this will work or even be relevant, but I have noticed that in some occasions when a sheet has been extensively modified, it can refuse to repaint (rather than calculate).
This problem mainly happens with excess amounts of named ranges or conditional formatting that have been simplified/removed.

If you scroll past the cells that are not calculating then back, do they refresh?
If they do then copy the sheet to a new workbook and see if the copy sheet works as expected, if it does, copy it back to the source workbook and delete the original then rename the sheet accordingly.

It might be worth a try in any case, I suspect there are other scenarios where this bug exists.