The pre-installed cam controls the floodlight.
The primary camera, a Wyze Cam v3, that comes pre-installed in Wyze Cam Floodlight controls the floodlight and its settings. This includes turning it on or off manually or using automatic features like motion detection or Automations.
Related article: Wyze Cam Accessory Compatibility
If you add another Wyze Cam using the second USB port, that camera will work as a normal camera without controlling the floodlight.
Wyze Cam OG, Wyze Cam OG Telephoto 3x, and Wyze Cam Pan v3 are a few cameras that can also be powered by Wyze Cam Floodlight, but are unable to control it.