What OS are you using? Is it the same on the old MOBO?
Does your webcam transmit audio and video through USB together or use a mic jack?
Have you update the BIOS?
Installed all drivers for the MOBO, the USB bracket is just a straight connection from the MOBO to USB ports and have no circuits so...
A few months ago my local news station reported hackers can hack into PC webcams.
Wonder how easy it is for consoles and STBes?
With they would put a physical switch on these type of devices. Excludes cells and tablets since those are usually set down.