While playing in my Minecraft realms world I experienced problems with chunk errors. For example, while playing chunks refused to load and only did so when a block in that chunk was updated such as placing or breaking a block.
Another chunk error that has occurred to me, which may be different, but is possibly caused by the same issue is after I leave the realms and come back in Chunks go wild and flash scenes of other chunks worldwide normally causing me not to be able to move and certainly not to see. To fix this I have to close the game out and go back to the launcher.