When importing converted DNG files into Lightroom Classic they get automatically converted to B&W even though the import Profile is set to None and all Presets are set to defaults. This does NOT happen when converting the same files with DNG Converter v11.3. BTW the compatibility is set to 7.1 and later.
Incidentally I've experienced this with Fujifilm X-T30 raw images.
This is exactly what has been happening to me! Fujifilm X-T30 and having to process RAF into DNG. The odd thing is it was working fine one week, then it swapped to B+W and applied a monochrome filter the next. I am not aware of updating the converter version in between but will check the version no. now.
Yes - due to a combination of old computer with not much power and Fujifilm not being fully supported in the software I have - I do need to change to DNG first. However, I did single out the issue once I downloaded an independant RAW viewer (Which was showing my camera images in colour) so then installed 12.2.1 (I was on 12.2.0) - and it worked!
I think I just replied to another answer of yours - Once I get a new set up then this issue will hopefully be a thing of the past! Thank you for your advice - it has been super helpful for a newbie like me!