chunk refuse to load

every time I load the realms there is alway a chunk missing in front of me. a huge 24 x 24 block. has been happening since I just signed up. please help. I really want to use this account. ps. at first, I could load from back up and it would do just fine. now it happens every single time. I even changed worlds several times. I hope that helps a little. I am using minecraft on the tablet. I do not know the exact version I am running. thanks for your help.