Craig,
When I try to follow your steps on 2 RAF files, I end up with 2 DNG and 2 RAF files in the folder.
I see both images in Lightroom Classic CC. All four files end up in Lightroom.
If I filter by file type in Grid View, I see 2 DNG and 2 raw files,
I do see that File Name does show the RAF actually as a DNG. That looks like a bug so I will check with engineering.
Rikk Flohr - Customer Advocacy: Adobe Photography Products