Anti-Theft System ?

I think I have an issue with my Anti-Theft System. Can anyone assist?
2000 Ford Expedition Eddie Bauer 4.6L with 276,000 miles

Symptoms:
Cranks but no start,
however, if I wait 15 seconds with key in on position it will start immediately. But if I crank it right away, after putting the key in, no start.

Procedures completed:
I have checked for fuel, spark, and electrical.

Verified code for EGR insufficient flow.
Pulled EGR: Found carbon build up.
Removed EGR, idle air control and throttle body, cleaned with throttle body cleaner per manufacture instructions, making sure no cleaner entered components and replaced.

Replace tubing from PCV to throttle body since it looked rotted.

Battery check:
12.16 volts sitting without key
11.94 volts with key in on position
10.71 volts when cranking
14.59 volts after starting

Crank Sensor
Replaced after back probing and did not fall between .5 and 1
Fuel rail compression: 38 and steady, 44 at initial key in run position.
Turn key on, fuel pump runs for 2 seconds and shuts off as per manufacture.

Electrical:
Checked all fuses visually and with test light.
Bench test relays with multi-meter for continuity
Inertia switch is set and never popped up, no accidents. Assume it is okay since fuel pump is running. Will check voltage to it shortly.
Engine light does not stay on while cranking.
I may have left off some tests as I have completed a lot trying to run down the issue. I am open to anything at this time.
I am leaning toward anti-theft system but I am stumped.

Let me know it you have a solution... Thanks

Sorry, forgot to mention no codes now. Did not erase any either. Using Bosch OBD II scanner.

Anti-Theft issue

Forgot to mention, Smoke test. Removed vacuum from brake booster and blew smoke into it. Found no leaks or smoke coming from vacuum hoses. Not to sure if it is that accurate.

Suggest you check fuel pressure. When you mention that if you wait 15 seconds with key on then it starts could be due to low fuel pressure. However the fuel pump only runs for a short time unless the engine starts.

When was the fuel filter last changed and also when was the fuel pump replaced?

That is one that I forgot. I replaced fuel filter last week. The family had this in Texas for the past few years. When I got it, I did most of the preventive maintenance on it. I did the fuel pressure test before during and after starting. All appear fine, ranging from 38 PSI to 44 PSI.

What is the initial fuel pressure prior to first start?

Battery needs to be charged also.

Anti-Theft issue ?

35 to 38 PSI. I left it on and no leak down. I will try it again to be sure as an additional check.
Do you think the battery would keep it from initial start up? That is weird, because if I leave the key in the run position for 15 seconds it will start right up.

Fuel pressure holding at 38 PSI.
Also checked and verified with multi-meter, all fuses in engine and passenger compartment. Some seem low at 11.6.
Fuse 20 (10A) Trailer tow stop and left turn lamp shows 34.9. After turning lights off shows 10.2. All other fuses checked out with light being turned on for lamp fuses. I know some of these wire looms are interconnected so I figured I would check them all.

You're not an old diesel guy that misses the "wait to start" lamp are you?

How worn are your keys?

Not a diesel guy and keys not worn out.
Just can't believe it actually will start if I wait 15 seconds. I am puzzled by this.
Just got back from shopping. Fuel Pressure at 35 PSI battery fully charged. Still on start at initial crank, but wait 15 seconds with key in run position and it cranks right up.