I can't say why you saw XMP files there before, but Lightroom does NOT create XMP files for DNGs. Does not. Does not.
Lightroom only creates XMP files for RAWs, not for DNG or any non-RAW file type.
Thanks for your help! I know it writes the data into the DNG metadata when I save it, but I've always been able, in the past, to also create a separate XMP file along with the DNG. I've done this for years with no trouble until today. I know it's redundant, but I liked having both options. Any idea as to why it did it in the past but not anymore?
The only answer I have is that I think you were mistaken. If you saw xmp files with DNG files, some other application put them there. Lightroom did not put them there.
I think I just figured it out. Bridge was generating them separately. Thanks again!