Interesting thing happened to me tonight. I uploaded 7 images using Deepmeta. Then I went to the 'suitcase' to check they were all there and saw that 11 images had been uploaded.
On looking more closely, one image was uploaded and showed as 'pending' with two different file numbers. The two files were identical except that one was missing the model release while the other had the release.
Another image was uploaded 4 times and had 4 different file numbers. Only one of those had the model release attached.
I deleted the 4 images that were missing the releases and kept the 2 that had them.
If you are using Deepmeta, you might want to check your upload queue to see that the right number of files were uploaded and look for duplicates that may be missing the releases.