After making the changes in the column setting, you can go to the gear button in the top right corner of the page and choose to save the changes to the current view or in a new view. Please note that the My prespective view is shared for all users and you will make the changes for the rest of the users too. For this reason server administrator permissions are required for saving any changes in the view. If you would like to keep the current My perspective view, you can choose to create a new view with the changes which can be saved as either private view or shared for a specific project.
You can find more details on the save options here
Please check the saving options again and let us know if further assisstence is needed.