You need to turn off band steering by creating separate 2.4 and 5 GHz networks, instructions are here:
@gunndm -- The BlueCurve gateway should be broadcasting on both the 2.4 Ghz and 5 Ghz channels, either using the same SSID for both bands, or, if you configure it, for different SSIDs for each band. Is this not happening for you? What symptoms? Older iPhones connect only on the 2.4 Ghz band.
You need to turn off band steering by creating separate 2.4 and 5 GHz networks, instructions are here:
It should be noted that you can only separate the networks if you DO NOT have the expander pods.
If you do have the pods, you have to unplug them and remove them from the BlueCurve app meaning you will not be able to use the pods anymore in this mode.
This seems ridiculous to me that we pay so much for a router that has such limited capabilities.