Lightroom Classic 7.3 Removes Older B&W Profiles when Applying XMP Presets, Converting Image to Color
If you apply XMP presets to an image in Lightroom Classic 7.3 that uses an older B&W profile (such as “Camera Default BW” or “Adobe Standard BW”), Lightroom will change the photo’s profile to Adobe Color.
This bug only affects Lightroom Classic 7.3, and Adobe is working on a fix.