Make sure these settings are set:


TENANT WIDE SETTINGS

https://smcsc-admin.sharepoint.com/_layouts/15/online/AdminHome.aspx#/sharing

This is already set for our Sharepoint Tenant.

Move to SITE SPECIFIC SETTINGS.




SITE SPECIFIC SETTINGS

https://smcsc-admin.sharepoint.com/_layouts/15/online/AdminHome.aspx#/siteManagement/view/ALL%20SITES


Leave all the rest as "Same...."


ADD THE CONTACT TO AD 1ST

First add the new person as a Contact using their personal email address. Make sure to place the in the correct OU.


NOW SHARE THE SITE TO USERS