This bug is in iOS 1.2.14.
I noticed That when I walked away from my tamed horses, they disappeared, and then seconds later reappeared. It also happened with my tamed dogs and chickens. And I searched.
I walked away a couple of blocks, and they disappeared, came back and they reappeared. When I came back from adventuring, my chickens were gone, then a few seconds later, reappeared. Very weird. 🤔
May not be a problem any more.
Related issues
Attachments
Comments

Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-32038.
Your additional information and observations are very useful, so if you can add them to the comments section of the parent issue it would be appreciated.
Please add a vote to MCPE-32038, and if you know of any steps to reproduce the issue reliably please add them there too.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Feedback – 📖 Game Wiki