Faulty noise cancellation - broken mic suspect

My WH-1000XM4s have extremely poor noise cancellation performance - about the equivalent of lightly placing your fingers on your ears. The microphone also doesn't work properly and I suspect this is the reason for the faulty noise cancellation.

They are useless on buses with noise cancellation turned on. Makes all these loud explosion noises which are in sync with the engine hums. I'm pretty sure it's the mic because in my testing, the mic doesn't pickup ANYTHING at all normally. However if I shout extremely loudly it'll catch the peak of the loud parts.

Any thoughts on my situation? I plan to follow the Microphone Array Replacement guide on this site, I am completely new to fixing stuff. I would love help sourcing replacement parts. On aliexpress I've found these "Original mic noise reduction label for Sony WH-1000xm4 xm3 xm2" but chatgpt says noise reduction labels are not what I need and most likely I need a full Replacement Noise Reduction Microphone but I'm not sure where to find these. I am based in Australia.

Thanks all