My TV is TCL Roku 552401 and My soundbar is TCL Alto 7+ 2.1 w/ wireless subwoofer. Upon receiving and hooking up my soundbar through HDMI ARC, it worked fine for about 4 days after purchase. On the 5th day, it was no longer playing any sound out of the soundbar and the sound was coming back out of the TV speakers. I search for the device under CEC settings and it detects no devices. I have tried resetting my tv to the factory settings. I have tried using a different HDMI cable. It still will not be detected. HDMI ARC setting is activated within the audio settings. I have set the audio settings to PCM-stereo and still no sound.
The first two days there was the subwoofer icon. Then it still had the subwoofer icon but it was frozen on 20. The volume would still go up and down but the tv only said 20. Then a day later it automatically switches back to the tv speakers with the speaker icon. Also, there is no System audio control settings under Control other devices