Hello rathianhunter
Usually, when you create a new account, the default level of microphone may not be 100. However, once you adjust the level, it remains that way, unless the app you're using the mic with overrides the settings.
That said, if this only happens when a new user logs in for the first time, it's normal. On the other hand, if the same user logs in again and the mic level is back to default, please check if the app has its level configured accordingly.
You can also try this:
Right-click the speaker icon from the notification area, click Sounds, go to the Recording tab, double-click the microphone you're having issues with, go to the Advanced tab, and uncheck both the boxes in the Exclusive Mode...