I am looking for help.

I have a deep well with a submersible pump. When taking a shower or filling the washer, the water will turn off for 30-60 seconds and then start back up. I replaced the pressure tank with a new 100# tank. Pressure is set at 28 lb (I checked it). I also replaced the pressure switch with a Home Depot brand 30-50 switch. It did not solve the problem. Thinking the new switch may be defective, I replaced it again, but it still does it. Can anyone help?