That doesn’t mean the device is supported. Apps have to declare explicitly which devices they support, based on modelId and manufacturerId.
The LEDVANCE SMART+ app supports these modelId’s:
PAR16 TW Value
PAR16 TW Z3
PAR16 DIM Z3
PAR16 RGBW Z3
PAR16 RGBW Value
As you can see, the modelId of your light, PAR16S RGBW, isn’t listed, so it’s not supported by the app.
You can add the device as a generic Zigbee device (you call it an “unknown Zigbee device”), and it will mostly work.
I don’t know why the <group> app doesn’t support it though, it’s probably best to ask in the app thread.
