Multiplayer issue is when the other tablet is joining the world, it will freeze the world on the other tablet, This happens to the infinite and old worlds and not super flat worlds.
Two tablets are:
iKon IK-800D, and xTouch F81

Steps to reproduce:
1. Have 2 phones with Minecraft PE
2. On the first phone, Go to world selection screen
3. Click on the world or create new world in the infinite
4. On the other phone, Check the 2 phones if connected to the same WiFi network, and then join the world
5. Wait for few 3 seconds moving your camera