XB10 Unified WiFi Issue with Galaxy S24 Ultra, Splitting 2.4 GHz and 5 GHz Fixed "Couldn’t Connect to Network"

I’m sharing this in case it helps other XB10 users experiencing the same issue.

I have an Xfinity XB10 gateway and a Samsung Galaxy S24 Ultra. With the XB10 using one combined SSID for the 2.4 GHz, 5 GHz, and 6 GHz bands, my S24 Ultra could see the WiFi network but repeatedly showed:

“Couldn’t connect to network.”

The security mode at the time was WPA3-Personal Transition.

I then split the WiFi bands into separate SSIDs. After doing that:

• The S24 Ultra connected normally to 2.4 GHz

• The S24 Ultra connected normally to 5 GHz

• I changed the security mode to WPA3-Personal only, and it still worked

This appears to rule out WPA3 compatibility, a defective 5 GHz radio, or a WiFi hardware issue with the S24 Ultra.

The issue seems to be related to the XB10’s unified SSID / band-steering behavior, or possibly a stale wireless state that was cleared when the bands were reconfigured.

Current workaround:
Keep the 2.4 GHz and 5 GHz bands on separate SSIDs. WPA3-Personal works normally in this configuration.

I’m posting this both as a workaround for other users and to see whether Xfinity can confirm if there is a known XB10 firmware or band-steering interoperability issue with modern WiFi 6E / WiFi 7 Android devices such as the Galaxy S24 Ultra.