Thank you for posting this question in the User Community. Unfortunately, I cannot think of a reason that Vital Sign Parameters would not be populating for 2 of your users. Users do have the ability to manually remove the VS Parameters from the assessment if they chose, but there is not a permission that would cause the parameters to not show. I would recommend having your users clear their Cache and Cookies to see if that helps, otherwise, you may need to submit a ticket for further investigation into this matter.
Thank you for being a valued Axxess Client!