Background: I have a SharePoint Site Template which previously we use in SharePoint 2010 but now upgraded and being used in SharePoint 2013. There is a Task list in that template where we have modified its columns (deleted few of them) and display only desired ones.
Problem: The problem is, when we create a new site using that template in a new Site Collection (in SharePoint 2013) it works fine and displays only that columns which are required. However, when we create a site using that template in any of the upgraded site (from SharePoint 2010 environment) it displays all of the fields in the Task list and do not keep only the desired ones that we did not delete. We have tried multiple scenarios and ended up that it could be the issue with the upgraded sites only.
Even if we create a new Task list in a Site Template of SharePoint 2013 and delete few of its column and again create a site in upgraded sites (from SharePoint 2010), it shows the same behavior that it creates the deleted columns automatically.
Is there any difference in SharePoint 2010 and SharePoint 2013 OOTB Task list that could create this issue?
Any thoughts how we have fix this issue? We do not need the deleted columns to be recreated on site creation using that Site Template.