I do apologize for the delayed response. Here is a download of the world. As I mentioned in the post, this bug was NOT reproducible on a singleplayer world, but was reproducible multiple times on an active Realm. I did manage to get all of the cats through the portal one by one on my current realm, but I have a couple of backups for testing if necessary! Still really not sure what was going on, or if it will even be reproducible.
Polly Edaline
I do apologize for the delayed response. Here is a download of the world. As I mentioned in the post, this bug was NOT reproducible on a singleplayer world, but was reproducible multiple times on an active Realm. I did manage to get all of the cats through the portal one by one on my current realm, but I have a couple of backups for testing if necessary! Still really not sure what was going on, or if it will even be reproducible.
https://mega.nz/#!vtoFnIZb!Pw5oqJ3KzcKBAaqm992oufNKJ95q0RND_zci3_QW6sg