I’m going to guess they are referring to the fact that after the iOS 13 update, iPhone users can no longer download and import .mcworld files easily like we used to be able to. Before iOS 13 we could download the file and simply click on “open in Minecraft” and it would import immediately. After iOS 13, the “open in Minecraft” option no longer works. I’ve seen a few lengthy workarounds for it, bu I haven’t found an easy solution and I haven’t tried the difficult one.
Either way this isn’t a Mojang issue, it’s an Apple issue.
I have the same problem. I thought maybe I was just going crazy. I created a fenced area, with their work blocks and beds. Then I basically bred them. I had several of them in this enclosure to make sure I could monitor them. They stayed there for about half the day. My WiFi cut out, when I got back on the game, they were all gone, and I only 2 left out of the 10 or so that wondered around the village
The seed this is happened in is 1299403684 And position 65, 73, 144