Chosen Solution

Is there a way of opening the microphone part and cleaning it or replacing it? Thank you

Or could it be a software issue/setting with my iphone, will run futher checks tonight. Thank you

Hi Gualtiero ! It may be a battery failure. I suggest you to follow the following tutorial: PowerBeats3 Wireless Headphones by Dr. Dre Battery Replacement

I had the same issue. The microphone was only picking sound when knocking on the case. I dismounted the mic housing (the controls on the cable) and realized that the original glue turned into some ugly greasy gel-like thing that stuck the mic. After cleaning it, I glued it together (with the B-7000 glue) and everything works like a charm.