Hi All, in desperate need for some assistance to help build confidence in using growthbook I'm having issues with Multiple Exposures

25 users (21.01%) saw multiple variations and were automatically removed from results. Check for bugs in your implementation, event tracking, or data pipeline.

My implementation: HTTP SDK in next.js w/ GA4 & BigQuery

<Script
        strategy="beforeInteractive"
        src="<https://cdn.jsdelivr.net/npm/@growthbook/growthbook/dist/bundles/auto.min.js>"
        async
        data-api-host="<https://cdn.growthbook.io>"
        data-client-key="[REDACT]"
        data-decryption-key="[REDACTED]"
      />

Now i can appreciate that

id

which is passed in will come from

gbuuid

and my reports will be based off google analytics

anon_id

and that there is scope for those to deviate, what I didn't expect was that by using CMD+R i could get myself from variant 0 to variant 1 Reprod (demonstrated in this loom) I go to a page where the experiment is (e.g https://www.addtoevent.co.uk/listings/singers) Observe from dataLayer that I am variant 0, hit CMD+R and see that I am variant 1 and compromised Does anyone know why that might occur? I've not made any changes to an inflight experiment. any pearls of wisdom greatly appreciated.

Hi @polite-afternoon-32745. Sorry you're having trouble. I watched the Loom and visited your site. I saw that the variant changed for you, but I wasn't able to replicate that when I visited the site. The first thing that comes to mind for me is that the cookie isn't being preserved for some reason (you shouldn't need sticky bucketing here). In Dev Tools, if you go to the Application tab and look at cookies, can you confirm whether the gbuuid cookie is consistently the same after refresh?

Hi @strong-mouse-55694 appreciate you looking to help with my specific issue 🙏 Brand new chrome profile (for brevity i left the filming of that out but it's evidenced by the face i get the cookie popup to) -- this also means no chrome extensions that could meddle https://www.loom.com/share/aab3b6f974994fd5aeb3d26e25614c92 I visit the page go to cookies and observe there is a gbuuid which starts with '64c' I spam CMD+R a couple times and suddently my gbuuid starts with '351'. that shouldn't be possible should it think panic I guess i should start by reading through: https://cdn.jsdelivr.net/npm/@growthbook/growthbook/dist/bundles/auto.js

This isn't a GrowthBook issue exactly. It's that cookie popup. I think I didn't get it because I'm in the US?? It seems like it's clearing the cookie, which is why you're getting a different one on reload. Another user was having a similar issue. Let me find the response and share it.

Thanks @strong-mouse-55694 that was driving me crazy I believe you are correct. Marking this cookie as necessary/whitelisted halts the issue I was seeing in videos. Appreciate you taking the time. Relaunched the experiment and will hopefully be looking at <=1% multiple exposure 🤞

Sweet! It's something I flagged for us, too, to see if we can make this easier or at least call it out more clearly in the docs. Lmk if you continue to have issues.