I created a simple seed farm on my phone with a red-stone clock one observer pointing into another. I did this one on top of the other and put a dispenser on two ends on the same side put a grass block in front of the observers. I then put bonemeal in the dispencers and the second I tried to start it I lagged out after breaking the grass a few times I am unsure if this is a storage issue with my phone or a bug but figured it was worth reporting.