External Collaborators Can't Sort Rows & Columns


My team has a Smartsheet in which there are external and internal collaborators. We are experiencing an issue of our external collaborators not being able to sort columns and rows. The external collaborators have Smartsheet licenses but unsure of the type of Smartsheet product they have.

Are the external collaborators not able to sort rows & columns because of the potential differences in the Smartsheet products each organization has? Or could this be something else? FYI, we have no filters and no locked rows/columns.

Thanks in advance for any help.