split into multiple ssids

I have the new xfi gateway that offers 3 bands - 2.4Ghz, 5Ghz and 6Ghz. Can I split into 3 distinct SSIDs? When I try to do this via the xFinity app - even by naming the 3 SSIDs with distinct names and passwords - I get the error - "Something went wrong. These settings couldn't be updated. Please try again later."

I have tried different options including not broadcasting the SSIDs but no different result.

I have even restarted the gateway and attempted the above ...still same result with the same error message.