Hello Everyone.
What I have one the FW13: System: Intel® Core™ i5-1135G7
Recently, The microphone simply stop working. Its there driver loading, its being detected and all but the issue is that its not detecting any noises. I am unsure if there was a Windows Update that caused this issue.
Welcome to the forum.
Check your mic disable switch?
If not that, I’d suspect your webcam cable, it’s been the cause of other people losing microphone. Not sure how to test in windows, or linux either for that mater. 
The microphone signal is separate from the webcam & it’s video signal. Mic is i2c connected to an audio processing chip on the laptop motherboard / mainboard. So the audio chip may show up as fine, even if it can’t talk to the microphone. Replacement cables are available in the FW store.