Minecraft pe doesn’t work with internet

I'm assuming you're on a multiplayer server.

To get past this, you have to type "/register", then a space, followed by any password you'll remember. Once you do that, it'll say "you have been authenticated", and you're free to (metaphorically) run naked in the rain, which is actually rather overrated. You'll have to do this again for every different server you go on that asks you to do this. When re-joining, it'll ask you to login, so you do the same kind of thing, typing "/login", a space, and the password you typed in last time. After that, you can move around and do whatever.

If this is single-player, then I have no idea what the hell is going on, and that is something for Mojang to answer.

Hope this helped.

Well, first of all dark room mob spawners aren't very effective unless put to a large scale. I would suggest that you make a 30 by 30 platform which can have another platform 10 blocks above, it has to be nighttime and no other mobs are allowed to spawn around the building, also, you have to have holes in the floor with trapdoors, you can make the trapdoors activate at the hit of a lever. The reason why you want to use trapdoors that are open is because mob AI detect trapdoors as standing blocks whether they are open or closed, also, no water because of update with drowned. Also, its a good idea not to build on slime chunks, can decrease entity spawning. Lastly, one thing for you to check, do /kill @e to reset the entity spawning in area.