Lions Mane Growing Help

Hi! I am new to growing mushrooms and have been trying to grow lions mane from a bag. It has been developing these brown/black spots that the internet said was bacteria, and I was wondering if there is a way to get rid of it? Should we cut it off? Any advice would be very appreciated!

I'm currently growing my first Lions Mane at home but have foraged them for years now. The color you see is usually age or bacteria. How are you growing them? Is there plenty of airflow? Cool temps? Personally I would cut away the discolored part and use what I can. Leave any new growth under for potential future harvests.

Edited to add. After another look at the pictures most of it may just be age. You want to harvest when the 'teeth' are obvious and prominent.