Webcam - sometimes yes, sometimes no

I have an ASUS VivoBook with a Logi C270 HD WebCam. Sometimes when I try to join a meeting, the WebCam works fine. At other times, the Zoom page just goes into an endless loop and never opens the meeting. In that case, I usually have to close all windows, unplug the camera, restart the computer, and join the meeting without camera. I've tried joining a meeting and then plugging in the camera, and that usually sets off some loop that results in my leaving the meeting.

I've check the permissions and security, and it looks OK. I've tested the camera outside of Zoom, and it works OK. I've not been able to detect a pattern of when the camera works on Zoom and when it doesn't.

Any suggestions?