Hi @jeremyjustin during my checking, I only use Zoom and Snap camera just after start PC. As additional info, USB live camera (real camera) can be used only from one app in my PC, I mean, if Zoom is displaying my face via USB live camera, Snap camera app cannot use it, and the same for Snap camera case. USB live camera cannot be share by two apps. I wonder this also could be the issue. I think my problem could be nothing to do with Zoom, so I would close this question here. Thank you for your help jeremyjustin. 😊
Ok @yozo thank you for getting back to us. There are definitely some apps that are not good with sharing! Just one more thought, when you start your computer sometimes programs will load up and run in the background without you knowing. If you can get to Task Manager I believe you can check there, I am not sure if this will help but just in case https://www.onmsft.com/news/closing-apps-windows-81-requires-you-drag-and-hold
I know this hasn't "fixed" the issue per se but if you have found this post helpful, please feel free to click "Accept as Solution" below. Others will still be able to add to this posting. Thanks!