If the cam is plugged into USB 2.0 port, try plugging it into a USB 3.0 port.
If the cam is plugged into USB 3.0 port, try plugging it into a USB 2.0 port.
Try connecting the webcam to a USB port that is connected to the Motherboard directly, if it already is, connect it to one that's not.
I was having this same issue Thank you so much "So Who You" switching from a 3.0 to a 2.0 port fixed the issue. I really appreciate it