Randomnly losing half a heart

Samsung Galaxy S7 Edge, not rooted.
Minecraft 0.16.1 bought from google play store.
Playing on PE Realm I own logged in as Safeness Friend through xbox live.
This has only started happening in the past day or so (that I've noticed)
Every now and then I just lose a half health.
Here is a video of me recreating the bug 3 times.

https://youtu.be/EQEfVD7VjC8