The Link Category could be set to a specific Secure Role. To change this navigate to:
  1. Core > Communication > Resource Board > 
  2. Select the Persona for the Resource Board Post
  3. Click on the Post
  4. Click Manage (with a Gear Icon) on the Link 
  5. Click the Gear Icon in the upper right hand corner 
  6. Remove the Secure Role from the right box as this will only display to that specific Role(this way it displays to all Roles once logged in to the Resource Board), or Select and Add the Roles from the left box, into the right box by clicking >> which should have access to this. Because it is on the Resource Board it is only accessible to users who login and is not a Public Post. However, if you do not want it clickable to certain Roles that you publish the post to, then only Select the Roles you want to see it  in the Secure Access area.
  7. Click Save