If you click on the entry for the device, you should see a message indicating why the yellow bang is displaying on the icon. Please send us a capture of that message.
In general, the engine is identified as UHD in cases where access to the memory is poor. In order to display as ARC graphics, you need both DRAM controllers - both Channels - active and synchronized. If you only have memory installed in a single channel - as it appears to be in this case - you are only going to see it display as UHD graphics.
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