It appears that there is sound on the TFT you are using and the Pi is recognizing it. You can run aplay -l from the terminal to verify. You must have the Wolfson Audio chip mapped as the first device or sBitx won't start.
?
card 0: audioinjectorpi [audioinjector-pi-soundcard], device 0: AudioInjector audio wm8731-hifi-0 [AudioInjector audio wm8731-hifi-0]
? Subdevices: 0/1
? Subdevice #0: subdevice #0
