My question would be why chunkloader does not allow 3x3 to protect it, only 1x1? And so, I can only put three.
MyMChunkLoaders Increased minute cost from 5 to 10 Increased offline multiplication from 3 to 5 Changed online chunk limit from unlimited to default 9, patron1 12, patron2 16, patron3 32 Changed offline chunk limit from unlimited to default 3, patron1 6, patron2 9, patron3 16 According to this you should be able to have one online chunkloader (iron block) set to 3x3 chunks and one offline chunkloader (golden block) set to 1x1 chunks. Are you certain that you do not have any other chunkloaders on your island?
I've only dropped one piece (golden block) and because I'm alone, so no one else can put it down and I did not put it in any dimension. But if I understand the offline chunkloader can only be 1x1?
That is correct, the reason being that when you log out the chunk loader will expand from 1x1 to 5x5. However, I am unsure as to why you cannot activate a 3x3 chunkloader in an iron block as you should be able to with the default rank. I would recommend trying to run /cm list [your in game name] in game and see if there is a chunkloader that you are unaware of on your island.
And if you find one that isn't really there.. slap down a chunk loader and break it to update the area.