I am attempting to use a USB webcam with a web browser. Specifically, the webcam is a Logitech HD Webcam C615 (which is listed as compatible at https://elinux.org/RPi_USB_Webcams), and either Chromium or Firefox as the web browser. I've tried a couple sites, including https://www.onlinemictest.com/webcam-test/ and Google Hangouts (and a few others), but although the webcam is detected, the test fails, with messages like "The video track is paused" (or muted).
The webcam is directly connected via USB (no hubs or anything) to a Raspberry Pi 4 running Buster. I am able to successfully capture an image with
fswebcam cam.jpg -S 20, so the webcam isn't totally unrecognized.
Are there additional steps that I need to take, such as installations or permissions? Is a different webcam likely to work better?