Varying manifold pressure??

Exactly as the title suggests, got a new turbo and wanna go back through my set up, my idle was never perfect. But I don't get why. I turnoff everything off and put it to open loop, I start the car and adjust the idle base table until the idle is bang on everything from start up until running temperature, sat at -75. Then I turn on idle ignition control, and turn it to closed loop. She's honey sweet. Turn the car off and start it again and it's now idling high at -65, I put it back to open loop and turn off idle ignition control. Go back in idle base position and adjust it to run at -65. Turn everything back on and she'll run at -65 but next time I get her out the garage. I'll start it and it'll be reading -75 and be oscillating. Has anyone else had this. I've gone through vac lines and cleaned the throttle but it was clean. All I can think is to disconnect the dump valve and see if it's that?

Thanks in advance.

P.s it's a version 6 impreza with a ej207 bottom end, 6 speed gear box, fmic, 800cc injector, gtx3071r, 3 inch turbo back exhaust, 3 port boost solenoid, uprated intake pipe and 57i induction kit. And running the link plug in ecu.

Update, I've taken the idle control valve out and cleaned it. Turned everything off and went over the idle base table. Perfect. Left it all off and drove it. Perfect. Turned the vehicle off and back on and boom high idle. Go back in adjust the number from 160 to 215 ish and she's perfect. Leave it over night and it won't run. Turn the numbers back down and she's fine again. Any suggestion would be great?

Any chance there are some HAAT (Hot At All Times) 12V pins on the ECU that are loosing power? For example do you have a battery disconnect?

Perhaps the tuning software isn't keeping everything in flash it should (ie, so not having a proper HAAT exposes a bug from the tuning software).

Ill check that all the plugs are properly connected, but I don't know why I see different manifold pressures. at one time its -75 and another time its -65. I'm gonna check it all for any vacuum leaks etc but I just wondered if anyone had ever come across this before and what they did to resolve it?

Sorry my background is more in the electronic throttle Subaru engines. Does the EJ207 have a mechanical fast idle valve on the throttle body? It could be either a valve that pushes open the throttle or a valve that bypasses extra air. If that is sticking or otherwise malfunctioning it can cause inconsistent idle. Usually they operate off coolant temperature, sort of like a thermostat.

Yeah my version 6 inlet manifold has a stepper bypass valve, i've cleaned it and where it sits but I didn't pull it in or out but I'm a take it off and plug it in and see if it's moving and clean it all again. Thanks for your reply