I checked it and found a few issues.
(1) Your video files do include audio. However, I noticed quite a few files are corrupt in that they lost the last chunk of data. I have reported it to our engineers. It is likely caused by Windows update, which probably created some new compatibility issues. We will fix it ASAP and release a new version Webcam Security Camera app to the Microsoft (App) Store.
You can also switch to CameraFTP Virtual Security System software (VSS). It is a much more powerful program than the Webcam Security Camera app. VSS supports multiple webcams, IP cameras and DVRs. It can use a PC as a CCTV DVR system. Better, it supports both local recording and cloud recording. So you don't need to buy a DVR/NVR.
To switch to VSS, you can log in to www.cameraftp.com and delete your current camera. Then download and install VSS software, then click Add to add a camera and select a webcam.
(2) You ordered x camera licenses, but you have more than x cameras. It is ok to have 1 or 2 more cameras for a short period of time for testing only. Otherwise, you need to order enough camera licenses.
(3) You ordered a motion-recording plan. Your camera should upload only when a motion is detected. However, it seems they are configured to upload continuously.