When setting up a Wi-Fi connection in the 2.4 GHz and 5 GHz dual-band Keenetic models, the same network name (SSID) and password are used by default.
This feature was made for the convenience of users. With the same SSID in 2.4 GHz and 5 GHz bands, client devices will not need to reconnect. The client device (smartphone/tablet/laptop etc.) will choose which 2.4GHz or 5GHz access point to connect to based on the qualities of the data environment, signal strength etc. This mechanism is called Band Steering. You can find more information in the 'Band Steering' article.
If you are not satisfied with such an algorithm of device operation and want your networks to have different names, you can change them manually in the router web interface: 'How to change Wi-Fi network name and password?'. If you use different SSIDs, you will be able to select the correct access point to connect to.