You can not disable SSID broadcast when Extended Range is disabled. Follow the steps below to disable Extended Range:

Step 1: Log into the Router by entering its IP address into a browser. The default IP address is https://192.168.1.1. The default username is admin with a password of admin. They are case sensitive.

Step 3: Click "Wireless" and then click "Basic".

Step 4: Select "Disabled" and then click "Apply".