Flutter SDK: Mixpanel User Profile Merging Issue Explained

Ari T. · 2025-05-13T08:59:01.783Z

Hi, I’d like to ask about an issue we’re facing. We’re using the Flutter SDK and calling `.identify()` after user login. However, we noticed that events from different users (with different UIDs and using different devices) are somehow being merged into one user profile in Mixpanel. The `UID` and `name` are passed correctly as event properties based on the logged-in account, and we confirm `.identify()` is called properly with the correct UID. But still, both users’ events appear under the same profile. I’ve attached a screenshot showing an example of this issue, where events from user A (UID_A) and user B (UID_B) are shown under one Mixpanel profile. Any idea why this might happen or how to prevent it? Thanks!

Flutter SDK: Mixpanel User Profile Merging Issue Explained | Mixpanel Community

3 comments

· Sorted by Oldest

Thena
APP
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Hi Ari! Julianne from Mixpanel Support here. As a bit of background, .identify() is used to link together anonymous IDs and the known user ID into an identity cluster. From the screenshot provided, it appears that at some point the dfc... and 6eeb... user IDs were identified to the same cluster. Once in the cluster, events tracked to either known user ID or any of the anonymous IDs will be tracked to that one Mixpanel user. Do you expect multiple users to access your platform on one device? If so, do you call .reset() at any point? Not calling .reset() at logout when multiple users share a device is the most common reason that multiple identifiers end up in the same cluster. The ID Merge docs have an example of the calls if you expect multiple users on one device.
Thena
APP
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Hi Julianne, Thank you for the explanation! Yes, we do expect multiple users to access the app on the same device, and we are currently implementing .reset() during logout. However, this issue might have occurred during an earlier POC phase when .reset() was not yet implemented—so two distinct IDs may have been merged into one cluster. Is there a way to correct or separate these IDs now that they’ve been merged? Thank you so much for your help! Best regards,Ari ThopanTo unsubscribe from this group and stop receiving emails from it, send an email to .
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Email text may have been truncated. Please review in Zendesk ticket.
Thena
APP
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·
Hi Ari! Thanks for the response. Just as a heads up, all responses on this chain are synced to the public Slack thread. Not having the .reset() call during the POC phase could be the cause of the behavior seen. If users were identified to the same cluster during the POC, their events would continue to be treated in Mixpanel as though they are one user. Unfortunately, once IDs have been merged into an identity cluster, the process is irreversible within Mixpanel. There is a workaround that involves exporting all of the data for the affected user, issuing a GDPR delete to remove all data associated with the user (this also deletes the identity cluster), and then re-importing the corrected data. This would also resolve the issue moving forward since the user IDs would no longer be part of the same identity cluster.

Thena
APP
·
·
Hi Ari! Julianne from Mixpanel Support here. As a bit of background, .identify() is used to link together anonymous IDs and the known user ID into an identity cluster. From the screenshot provided, it appears that at some point the dfc... and 6eeb... user IDs were identified to the same cluster. Once in the cluster, events tracked to either known user ID or any of the anonymous IDs will be tracked to that one Mixpanel user. Do you expect multiple users to access your platform on one device? If so, do you call .reset() at any point? Not calling .reset() at logout when multiple users share a device is the most common reason that multiple identifiers end up in the same cluster. The ID Merge docs have an example of the calls if you expect multiple users on one device.
Thena
APP
·
·
Hi Julianne, Thank you for the explanation! Yes, we do expect multiple users to access the app on the same device, and we are currently implementing .reset() during logout. However, this issue might have occurred during an earlier POC phase when .reset() was not yet implemented—so two distinct IDs may have been merged into one cluster. Is there a way to correct or separate these IDs now that they’ve been merged? Thank you so much for your help! Best regards,Ari ThopanTo unsubscribe from this group and stop receiving emails from it, send an email to .
Received via email
Email text may have been truncated. Please review in Zendesk ticket.
Thena
APP
·
·
Hi Ari! Thanks for the response. Just as a heads up, all responses on this chain are synced to the public Slack thread. Not having the .reset() call during the POC phase could be the cause of the behavior seen. If users were identified to the same cluster during the POC, their events would continue to be treated in Mixpanel as though they are one user. Unfortunately, once IDs have been merged into an identity cluster, the process is irreversible within Mixpanel. There is a workaround that involves exporting all of the data for the affected user, issuing a GDPR delete to remove all data associated with the user (this also deletes the identity cluster), and then re-importing the corrected data. This would also resolve the issue moving forward since the user IDs would no longer be part of the same identity cluster.