Okay, after double checking the network adapters ...
Both are no real 100mbps adapter. I have fallen for false advertisment.
Because of the sound stuttering if I start a stream, I have created a short log.
Starting device, starting stream and restarting device.
My advancedsettings.xml @ \storage\.kodi\userdata
Code
<!-- Created using Easy Advanced Settings addon -->
<advancedsettings>
<network>
<buffermode>1</buffermode>
<cachemembuffersize>209715200</cachemembuffersize>
<readbufferfactor>4.0</readbufferfactor>
</network>
</advancedsettings>
Made another log with audio and ffmpeg logging. (If I done it right)