Photos deleting automatically from a shared album.

I was trying to delete all of my photos from my iPhone 5S in order to free up some storage space. I created a shared album called "backup". I did not invite anyone else to join, so only I would have access to the media files. I then shared all of my photos and videos from my iPhone onto the album. After the media was uploaded onto the shared album, I deleted the photos and videos on the phone. I even cleared my deleted photos album.

Unfortunately, after a little while, I looked at the shared album and saw that the photo count, which had been in the 2000s, started to count down backwards. The files were deleting themselves from the shared album!! Why might this be happening and how do I stop it?

I put my phone onto airplane mode for the time being to bide some time and try to find a solution.

Luckily, the photos from the phone were still available on the iPhoto stream on my laptop. I backed them up onto an external hard drive. However, the video files are not in iPhoto, and I cannot access them unless I allow my iPhone to access the T-Mobile network or to access the wifi network, at which point the files will resume being deleted from the shared album. Would appreciate any insight anyone may have on this problem. Thank you.