Snapserver considers two independent devices as 1 about snapcast HOT 2 CLOSED

Try using the --instance flag

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What client are you using on the Android devices? Snapweb? Snapdroid?
Every client is expected to identify itself with a unique ID towards the server. Snapclient is usually using the MAC address, but the MAC address of the host cannot be queried on Android, nor from a web client, so they are both creating a uuid on their first start and persist it for future use. You can see the unique client ID's in the client details in Snapweb and Snapdroid (the three dots button next to the client).
I guess that you synced your apps and data from the Pixel 4 to the Pixel 6, which will also sync the app-data, and so the Pixel 6 will appear as the same device. You can simply delete the app data for Snapdroid on the Pixel 6, so that Snapdroid will create a new UUID during the next start.

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