Recovery Mode fail?

Try booting Recovery from a wholly different network, or build a bootable installer on another Mac and swap that to this Mac and try booting that.

Basically there is an issue with your wireless connection that is preventing Internet Recovery Mode from working.

If any of the following are true about your network connection, you will not be able to reinstall macOS using Internet Recovery Mode:

○ The wireless network is configured to use a hidden (non-broadcast) network name or SSID.

○ The wireless network is secured with either WEP or WPA-Enterprise.

○ The connection requires certificate-based authentication / 802.1x

○ The connection requires the use of Proxies (where specific proxy servers must be configured in network preferences)

○ Captive Wi-Fi networks (where you click an “Agree” button to access the Internet)

○ PPPoE (where there is no router handling the PPPoE connection)

○ Failure of the router to provide a workable DNS server address, or providing 0.0.0.0. This typically is seen with a -2002f or -2003f error message.

Ref: OS X Internet Recovery Error 2003F (10.11.6) - ASC

Wouldn't know as I'm only going on the very limited information that you provided in your original post.

Although most of those items relate to connecting by wireless (items 1, 2, & 5, in order) there are a number of them that are just as relevant when connected by Ethernet.

For example, does your ISP provide you with Internet access via a PPPoE connection? Have you tried connecting to another network to see if this would help? Finally, I suggest that you make a Genius Bar appointment at your local Apple Store or Apple Authorized Service Provider to see if they can assist you with this.