If your camera goes offline frequently, below are some troubleshooting steps to resolve the issue for you:
Step 1: Ensure both the firmware and EZVIZ app are running on the latest version.
Step 2: Ensure that your Wi-Fi network signal is good. You can check the signal by connecting your phone to the same WiFi your camera connects to, entering More page > Settings > Device Network Tools > Check WiFi signal.
Step 3: If not good, you can try to move the camera closer to your router, avoid obstacles and interference such as wall, elevator, microwave, washing machines, and Bluetooth devices.
Step 4: If your WiFi router has an adjustable antenna, try pointing it in various directions.
Step 5: Try to change the Wi-Fi channel to a less crowded one.
Step 6: If possible, disconnect some devices you seldom use from your router.
Step 7: If your camera supports Ethernet cable, you can also try to connect it using a cable.
Step 8: If you have two EZVIZ devices and the other one is working fine, you can also try to switch the locations to further determine the issue.