From your description of behavior it seems to be the most likely cause for some page visitors not triggering the client conversion. For testing of KPIs we create tests with 100% participation so that all users visiting the A\B tested page will be included as test participants and so we can see right away if the expected conversion conditions actually generate results for the test.
I have a question about A/B testing. We created custom KPI with client script, tested this script, its works correctly. But when we tried to start test, it not counting our users and EpiServer don't insert client code to the page.
Could anyone provide more details about how it works?
How does it know, that user already existing or already passed test?
Because most of users don't get any client scripts for a/b testing. We tried from different browsers, we cleared all session data with cookies and etc. No results.
As I could understand after my investigation, if you already pass one test and start another, its already counting you as existing user. Also after you just pass the test, EpiServer stops inserting a/b testing code to client page.