After testing Tablepress out, I set up a live site and mirrored the setup.
The problem I am having is: I copied and pasted some dates form an .xls spreadsheet and pasted them into a Tablepress column. I set up the European date formulas but for some reason when you click on the column to sort it nothing happens or if you remove the formula the data is all over the place.
I have tried exporting the data as HTML, pasting it as plain text into a new spreadsheet, then importing it back into Tablepress as a csv file. I have also tried this by exporting as a csv file.
If I import the dummy data as a csv from the original test site all the date sorting works fine.
Any ideas what might be going on?