CAMERA UNAVAILABLE ACROSS APPS

Hi, I'm using Mac M1 2020 and updated to Ventura 13.4.1 and wondering why my camera stop working across apps (through FaceTime, Messenger, Photo Booth, etc..). I've tried to restart the Mac for times and quit all the apps then re-permit the use of camera for all of them but the camera still doesn't work. It's said on FaceTime "No Camera Available, To use FaceTime, connect a camera". What should I do??? TIA!