Task form fields not getting updated in list

Greetings,

We are facing a pricular problem, a task will be generated for approver. The field type in the task form are from SharePoint, these are People Picker/DateTime/TextBox/Notes.
In task form approver will add next step approver/ date of completion/ number of days/ and remarks.
On adding all the above mentioned fileds in task form non of the fileds get updated in the list. If the task form contains only 1 field it gets updated to the list.

We are using K2 BlackPoint and SharePoint list created from content type.

Thanks,