Hi Katrina,
I think this document with give an answer to both of your questions - https://helpx.adobe.com/analytics/kb/none-unspecified-and-unknown.html
It may be that at the time at event was fired the campaign variable did not have a persisting value. This could be due to the visitor not arriving via a campaign (such as direct traffic), or it could be improper campaign tagging.
If you suspect a campaign is improperly tagged, I'd recommend pretending to be a visitor, click through the campaign, and check the debugger to make sure the campaign variable is triggered on the following page.
Thanks