I have been having the same problem. I have tried 3 microphones and presonus barely picks up the audio. I have spent over 2 hours debugging, matching the sample rate of the mic in the windows properties with the studio settings, reset up the microphone over and over in the audio set up, restarting with each mic. (one was a headset mic, another a standard usb mic and the default laptop microphone). I even unplugged the laptop to run on battery good grief. I just get a buzzing noise and barely audible sound under the buzzing. On some microphones I can slightly hear the sound better coming in and others just buzzing.
I am running a fairly new laptop (a little over a year old) with windows 10, intel i7 cpu, 16 gig of ram. All of the microphones run completely fine in other applications. I have to load out files and bring them into audacity just to record audio.