[DuhSoDeadly]

Good afternoon,

I have been banging my head against the wall trying to figure this out.
I have a 2000 Boxster 2.7 L that just hit 100k miles.
It had a rough idle and misfire for a little bit so I replaced the spark plugs and coil packs.
That didn't fix it so then I had a smoke test done on the intake and didn't find anything obvious; tightened all connections just to be sure.
Eventually the car had no acceleration; and shut off on the highway.
Restarted the car, it ran for a few seconds, then shut off.
Eventually would not start.
Towed it to a mechanic and they said my fuel pump was bad; replaced fuel pump.
Still have crank no start.
Tested fuel pump connector, no power to the fuel pump.
Tested fuel pump fuse, 12 volts.
Tested fuel pump relay, junction 85 and 86 not getting signal to turn on.
Purchased bypass relay, pump turns on but still crank no start.
Thought maybe my fuel filter, but that wouldn't cause 85 and 86 to not turn on, right?
Searched forums and someone said immobilizer, but upon further research if the immobilizer was bad then my car wouldn't even crank? (Not sure if this is true or not)
ChatGPT says it could be my DME?
At this point, diagnosing this car is getting to be a bit more than what I can handle.
Another mechanic that specializes in Porsche's says it sounds like independent issues; one causing a rough idle, and another that's causing the crank no start.

Anyone have any guesses or corrections to my assumptions?