Diagnosis
The camera is stuck in its initial setup mode, usually because it’s not completing the handshake with your Wi-Fi network. The most common culprit is a 5GHz network or a network with special characters in the name or password.
How to Fix It
First, hold the sync button on the camera for about 5 seconds until you hear a voice prompt and the light starts flashing blue. This resets the connection. Now, go into your phone's Wi-Fi settings (not the eufy app) and look for a temporary network named something like "EufyCam_XXXX". Connect to it, then return to the eufy app to finish setup. During setup, make absolutely sure you are selecting your 2.4GHz Wi-Fi network, not the 5GHz one.
If That Didn't Work
If it still fails, your router might be using a channel the camera doesn't like. Log into your router's admin page—usually through a browser—and try changing your 2.4GHz band's channel to something common like 1, 6, or 11. Save the settings, restart your router, and then try the camera setup again from scratch.
Heads Up
If you have a mesh network, temporarily disable the "band steering" or "smart connect" feature that automatically switches devices between 2.4GHz and 5GHz. The camera needs a stable 2.4GHz connection to set up properly.