Version: 18.104.22.168 for Windows (on Windows 10 64bit)
A camera layer that is zoomed, resized, cropped and positioned is still draggable by mouse even if the layer is locked. (i.e. with the lock icon enabled; Manage layers -> lock layer)
The bounding box is locked, but the offset of the zoomed image inside the bounding box is still moveable. In essence, not all properties that affect how the layer is positioned are locked.
Let me know if you need me to send further details or send a video showing a repro of the issue.