The employee import template downloaded from the instance (Admin center > Employee Import ) shows an extra column called "GROUP" however this is not defined in the succession Data model.
Reproducing the Issue
Login to the instance.
Navigate to Admin Center > Employee Import
Download the Employee import Template
This will have an extra column called "GROUP" as a last column in the template
This is because, there is a feature "Dynamic Groups" (Legacy Not the Dynamic Groups 2.0 ) is enabled for the instance.
Create a CS incident to disable the legacy Dynamic Groups feature from provisioning. Howeve Dynamic Groups 2.0 must be enabled in place legacy Dynamic Groups to make use of the functionality.
KBA , LOD-SF-PLT-UM , User Management , How To