RedStone Functionality

I have some murky problems with redstone.
Will it doesn't work when a player is away from it.
I made an automatic chicken farm in survival ; made of redstone, repeater, powered rail, rails, chest in a minecart, redstone block, hopper and sticky pistons. So when I start up the system the chickens would lay eggs every 5 minutes(I guess) and the eggs will be consumed by hoppers.then they will be sent down to the minecart with a chest. after the minecart will get pushed by a red stone block and be sent to my harvestery where my eggs are at. it's a long way because my farm and my harvestery is far from each other (about150 blocks away) they will work perfectly if I stay WITH THE MINECART CONTAINING THE EGGS. But if I leave and do something else the minecart won't move at ALL I mean not even a bit. It will just stay at its position.
And when I come near it it will move again and do its job.
What I want u guys FIX (hopefully)is this annoying bug. The bug is caused when a player makes a long automatic (working itself machine) circuit/circuits, and goes away the red stone will not manipulate till a player is near it.
I hope the bug is comprehensible.
I am running MCPE latest 1.0.2.1
Thank u if u reading it this means a lot to me.