I've attached two photos and the detailed troubleshooting details.
Every photo on my phone has been duplicated in IMMICH. I took a small screen hot of just what it looks like.
This does seem to be happening overnight. I do have a backup process on the Database running nightly. But its set as a read only copy to a different location.
Background refresh has been off in the app since yesterday. But I woke up this morning to yesterday's photos duplicated. I couldn't duplicate it with the app open yesterday.