I Face Sennheiser Momentum 4 Microphone Static Issue In ANC Mode

I have been using my Sennheiser Momentum 4 Wireless headphones for about 3 years, and I have been experiencing ongoing software-related issues for quite some time. Since the day I purchased the device, I have never been able to update it, and it has never properly synced with the mobile app or connected to it at all. Despite this, I did not consider it a major issue because I was satisfied with the sound quality.

However, more recently, an additional problem has appeared—there is now a microphone malfunction. When active noise cancellation is turned on, and in both transparency and ANC modes, I constantly hear a crackling or static noise. This issue does not occur at all in passive mode, which leads me to believe the problem is caused by the ANC microphone.

My product came with a 2-year warranty, which has now expired. Still, experiencing these kinds of issues on such an expensive pair of headphones is very disappointing. I am requesting that my device be inspected and that the microphone issue be repaired, preferably without a high service cost. I also ask that the long-standing issue with updates and the mobile app connection be properly resolved.