Raw photos shot with Lightroom Mobile camera won't load...

Photos shot with the Lightroom mobile app camera on my Galaxy Note 20 in DNG can't be viewed in Lightroom mobile albums and previews can't be generated when syncing or importing to Lightroom Classic on my PC.

Manually copying the files from the phone to the PC results in files whose thumbnails I can see in explorer but still won't import properly to Lightroom Classic or open in Photoshop.  Lightroom says previews can't be generated and Photoshop says 'Could not open"LRM_20210204_181644.dng" because of a program error'.

This used to work with no problem.  Switching to shooting JPGs, the images import and sync without issue.

DNGs shot on my iPad Pro using Lightroom mobile work normally so this is related to Lightroom on Android Galaxy Note 20 phone.

Not only would I like to resolve the issue so I can shoot DNG with the phone, I'd love to hear ideas on recovering the images I already have shot and can't open!

Thanks!