Page is not refreshing

Hi All,

I have a strange problem with the Servoy paging in the web client. A foundset (100 records) is shown distributed over three pages.
Linked to the foundset is a calculated field that indicates whether a record has been selected or not.

isSelected = 1 is selected,
isSelected = 0 is not selected.

This is shown by means of a checkbox (ticked/not ticked) at the beginning of each line.
It is possible to select all records at once. De calculated field isSelected is set to value 1 in all records of the foundset.
All checkboxes on the first page are checked. The checkboxes on the second and third page are not checked, while isSelected = 1 for the records on those pages.
All pages that I have visited before selecting the records are displayed with checkboxes checked. The other pages have checkboxes that are not checked.

What should I do to make a checkbox is always checked when isSelected = 1, without beforehand having to visit each page?

Servoy version: 7.4.5

Thanks in Advance,
Marie-José van Zelst.

The calculation returned a 0.
Changing the return value from 0 to null solved the problem.