@Emma1211 Hi, Please also test with different Ethernet cables. If it still cannot help, please contact the local support to check warranty for you.

@Strommy Hi, Does the extended Wi-Fi have the same name as the main Wi-Fi? Please ensure that the device is connected directly to the RE and not to the main router's Wi-Fi. Besides, you can also try...

@ART89 Hi, You can check if this is consistent with the issue here. If so, please follow the troubleshooting steps in it. RE220/RE200/RE190 Keeps Restarting Automatically

@Andosh5 Hi, Can these devices connect normally to the main router? Make sure any Mac address filter or Access Control feature on the host Router is disabled. Please reboot the range extender. If it...

@vasanths Hi, You can download and install the beta firmware again directly.

@myhorden Hi, Please confirm if you input all the information correctly. If it still cannot work after that, please contact your ISP to check if they have done some special settings with this model.