When moving from #4 to #5 are these tests using different mboxes?
Are there any other tests running on the mbox used in #5?
You mentioned that you used "user.testFrequency" as the condition in #5. "User." variables are typically set by profile scripts in the Target interface rather than offline uploads like you describe in #2. Offline variables should be prefixed as "profile.". They'll show up in the profile view API without the "profile." prefix and you should just see the name. It looks to me like "valuedCustomer" is the variable that is set by your offline upload.
Please confirm there are no conflicting campaigns and that you are referring to the proper offline variable.
There is another way to achieve this, which is how i have achieved it. I am passing the Login username ( user credentails) as the mboxThirdPartyId in a REST Call to the target API. The call looks something like
var target_thirdPartyId = thirdPartyID; // user login ID