I have a sheep with the jeb_ nametag that disappeared when i reloaded my world. I had used a lead to attach it to a fence. Once it disappeared, part of the lead was still attached, but the sheep was gone. I tried opening older copies of the world, but it still disappeared every time, no matter where the sheep was located.
Thank you for your report!
We're actually already tracking this issue at MCPE-21416, so I will resolve and link this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
Quick Links:
📓 Issue Guidelines – 💬 Community Support – 📧 Customer Support – 📖 Game Wiki