well pump pressure range too much from highest to lowest
Your water storage/pressure/booster tank could be low on pressure. I would check it out and make sure it is set for the proper psi as the pump. 50psi pump cut off out mean the tank should have 50psi in it when full. Ideally a tank should be a mix of about 50 air and 50 water. If you have trouble with this, your newer tank could have a bladder or balloon issue.