Lombardo Salvatore

Furthermore I deleted old worlds and I tried to mining another area but nothing, when I join the same level it slow down. The only place where it is playable is the surface. I tried also to reduce the rendering but nothing

In survival mode I was digging an area about 20x20x2 blocks at a level around -10 (from the surface) at a certain point a zombie spawned from the dark and I killed him. Just after the environment get very slow. I got to exit from that area to the surface and the gameplay became normal again. Now on the mentioned area is impossible to play because of the same issue. Every time I got there it slow incredibly down . I've tried to turn on and off again, I killed myself but nothing worked out. Please help, I use iPad 2 with iOS 9.3.5