The saga continues.
Pulled the well pump up and we had water at the top of the pipe and it held there for 30 minutes so the check valve most likely isn't my issue.
I installed a ball valve on the house side of the Fleck 5600 Water Softener and can confirm that if I shut off the water to the house it still leaks back.
Shut off the irrigation completely and confirm it still leaks back.
So looks like I have a pipe problem somewhere between the valve at the house and the well head. UGH Next step i'm going to dig up where the pipe is and then have a friend of mine come over and pressure test both sides. I don't know which is worse, having to dig up the new front yard or having to jackhammer the new walkway to the house if the leak is under the concrete. UGH
What's weird is, now with the new expansion tank. Rises to 60 psi, then slowly drops to 50 psi (Slow as in 90 to 120 seconds to drop) and then once it hits 50 PSI it drops fast to the 30psi kick on and then repeats.