Hi there @wetracked.io, 

Welcome to the Community! 

I can see that you have engaged our Support team on this questions as well. Happy to share what a team member shared regarding this issue in case it helps any other Community members in the future! 

Essentially, the _kx values generated through the test campaign is not accepted by the Klaviyo APIs because the "tracking" is with a test user and not with a real, cookied user on the site.  The _kx value itself it meant to be anonymous in order to keep our customers and users safe - the _kx value itself is only meaningful within the context of Klaviyo - if that were not the case, anyone could use the _kx value to determine the email address of the user (including bad actors).
 
For this reason, it's not technically possible for you to determine a "real" kx from a test kx - only Klaviyo is able to determine the user/profile (including the validity of the kx value itself) from the _kx value.

Thanks for sharing your question in the Community, I’m sure it will help others users asking the same question as well!

-Taylor