Windows 10 IoT Core analog MIC input

On my Dragonboard i’m running the current release of Windows IoT Core (17763). Now i want to record some audio with an analog microphone.

So far, so good. Now all what i hear is some noise on my recorded file. I have connected a 3.5mm plug as follow:

Sleeve → J7 (MIC2_P)
Ring2 → J7 (AGND)
Ring1 → J7 (HPH_R)
Tip → J7 (HPH_L)

Also Looking at the available devices with PowerShell on my Dragonboard, i get the following Output

IoTCoreAudioControlTool l
d,r,Speakers (QCAUD Real Time (WaveRT) Driver for Qualcomm SoC),{0.0.0.00000000}.{2ff88fd6-f868-4e21-b4f3-7242c6e16692},100.0

d,c,Internal Microphone (QCAUD Real Time (WaveRT) Driver for Qualcomm SoC),{0.0.1.00000000}.{2fa3b5ac-187e-4cc8-a0d4-451a1b30b50b},100.0
,c,Internal Handset Microphone (QCAUD Real Time (WaveRT) Driver for Qualcomm SoC),{0.0.1.00000000}.{31fcf5da-b92e-4615-8ba8-c8ee4f3bea36},100.0

Tested with both audio capture devices (Internal Microphone and Internal Handset Microphone), same problem with both of These audio devices.
I don’t know what i’m doing wrong, did i connect something the wrong way? Hope someone can help me out.

Best Regards