Hey folks - I've been experiencing some issues with the results coming through for an experiment. There is no throttling on the sample size, traffic allocation is set correctly and distributed correctly across variants but for some reason we're seeing data trickle in. During the last two days we're getting only 38 users to the experiment but the page receives hundreds of views daily. We've restarted the experiment and nothing has changed. The URL targeting is set to simple match with the correct URLs added to the experiment. We've gone through big query and the settings are up to date. Admittedly, I am not experiencing this issue with any of my other experiment accounts but I'm unsure of what the underlying cause is. Has anyone else encountered this issue?

Same issue. This is greatly hindering our ability to run experiments quickly. We have more than enough traffic, but GB Results are showing like 1/100th of traffic/events (even tho users are indeed seeing the experiment at appropriate weights).

Hey, sorry you're having trouble. There's several possibilities of things that could be happening. To narrow it down: • Do you see the data in BigQuery, but it's not making its way to GrowthBook? • What kind of experiment is this (feature flag, URL redirect, visual)?

Hey @strong-mouse-55694, We're digging into Big Query to check data The experiment is setup as a visual, no feature flags or redirects.

Are you able to share the page where the visual experiment is set up?

@strong-mouse-55694 here it is. We are also looking into GTM to determine if our events are triggering correctly

I can see the experiment viewed event data in GTM.

@strong-mouse-55694 thank you, yes, we're speculating at this point to determine if there was a modification to the event or script that might be causing issues....still nothing certain at this point

Are you using GA4 for the event tracker?

yes

Great. It can be a little tricky sometimes. Did you see our guide on setting this up? https://docs.growthbook.io/guide/google-tag-manager-and-growthbook

Thank you @strong-mouse-55694, at first glance it appears that GTM was the issue, we're running another test now to verify but I am seeing that the data for total users to the experiment is considerably less than the data I am seeing in GA4 for total users to the same page (less than 10% in fact). I understand that the test cohort would be different, but it seems steep. I am trying to find some documentation on this but if you have anything handy, it would be much appreciated.

Do you see any of the experiment viewed data in GA4? Did you confirm that the custom event is configured in GTM to track the experiment viewed event with GA4?