A more thorough description of your process would be helpful, ie. amount of grain, amount of dough in water, temp of dough in water. In addition are you batch sparging, fly sparging, BIAB or no sparging?
How long do you let the mash sit, and do you check for conversion with an iodine test?
It sounds like you need to mix the grains up more, in addition, it sounds like you may be mashing with too hot of water. (I normally dough in with water that is at 167 degrees F)