Over Allocation not yielding/triggering the red individual flag...

edited 12/09/19 in Smartsheet Basics

I have a project where I have invited my resources to a project and they have accepted, but the red over allocation flag (red person icon) is not triggering.

Do resources have to be licensed users? 

I believe I have read on various community notes that the resource needs to be invited and accept the invite.

Is this incorrect?