https://gyazo.com/299e36aff70a95f669810f111fb48aa4
I can also replicate this by tossing something into the chunk and it disappears, but I can still retrieve the item.
https://gyazo.com/38ffd24102d77e87358505831e0a3322
These "Deadzones" make it REALLY hard to find pokemon to tame. I hope there's a fix.