The Orbi mesh system defines the same SSIDs for the primary WiFi network (for 2.4G and 5G channels) and if they are enabled, the same SSIDs for the Guest and IoT WiFi networks (for 2.4G and 5G channels).
This cannot be changed by the user.
Sorry.
A typical WiFi Extender (of any brand) can be set up with whatever SSID you want.
