Have the same problem with a Dell 3440 running win10, first time the camera stopped working was after a Windows Update, KB4537572, removed that and camera started working again.
But it stopped again a few weeks later and nothing appears in Device Manager and no camera hardware is detected when scanning for new devices.
Looking at windows updates from about the time it stopped there is only one showing KB4552152 on the 28/04 but that one says you can't uninstall
it
Tried to find a driver to manually install but can't find one on either the Dell or MS website. Tried about 3 suggested fixes from YouTube videos (there are lots) but cannot get camera working