The 2.4GHz channel is missing and dropped connected devices. Could not connect again nor connect to 5GHz so rebooted and 5GHz now available. Tried another power off reboot with only 5GHz appearing after. Obviously, the device is now a few years old and I'm wondering if the 2.4 circuitry has failed. It would be a pain to re-flash the firmware and I'm not confident it would work. Any ideas please?