In some network management apps or routers, there may be options to sort or filter devices based on their status or activity. While I cannot provide the exact steps for the Eero app, I can suggest a few things you can try:

Check for sorting options: Explore the different sections or menus within the Eero app to see if there are any sorting options available. Look for options like "Sort by Status" or "Sort by Activity" that may help you identify the latest device that joined the network.

Search or filter devices: Look for a search or filter function within the app. This feature allows you to search for specific devices or filter the device list based on various criteria. By searching for new or recently connected devices, you may be able to identify the latest device that joined the network.

Check device details: Even if there is no specific sorting or filtering option, you can manually review the details of each device to identify the new one. Look for timestamps or connection history that indicates when a device joined the network. Compare this information with the time of the alert you received to pinpoint the latest device.

If you are unable to find the desired functionality or need further assistance, I recommend reaching out to Eero customer support. They should be able to provide you with specific instructions or guide you on how to identify new devices in the Eero app.