Zoom web app shows only the virtual background or a green screen with Logitech C615

In Microsoft Edge, Zoom correctly displayed video from my Logitech C615 before I joined a meeting. After joining, it showed the virtual background without my image. With virtual backgrounds disabled, the video appeared solid green.

The webcam worked correctly in Microsoft Teams, Edge had camera permission, and the computer had two AMD Radeon R5 430 adapters plus Intel UHD Graphics 630.

I’ve checked the usual manufacturer guidance and our general knowledgebase, but I haven’t found anything explaining why Zoom detects the background while removing the camera image.

What can cause this behavior when the camera works in other applications, and what practical troubleshooting steps can resolve it?