Sir, i really appretiate all your inputs!

I should fly to california in a couple of months or so and join my son for a week or so.
Once there i will check on the crank sensor, i remember it was a pain to replace it, and if it is not a bosh, we will replace it. From here in MD i can only ask my son to do the straight forward checks.

I mention turning the key to the second position yet i think i asked to turn all the way before cranking. I think so because we were video conferencing yet will double check with him. The fact that when we did this the 4th try (the one he did try to crank) the car refused to crank seems to be an interesting clue yet difficult to decifer. It seems like the ?pcm? is getting a signal that something is wrong and disabling the crank.
I think we can exclude the engine starter motor and solenoid since i have verified that once the car starts i can restarts as many time as i want; i have tryied 4-5-6 times in a row. This also, i think, seems to tell us that the fuel pump should be ok. Unless the fuel pressure is still there from the previous start?

Glad you mention to check the trunk leak from the bottom side rather then from the trunk itself. At some point in the past i was trying to check the electonic in the trunk and it was not obvious to me how to access it.
I think your point that the anti theft tow sensor could be damaged is very interesting. I will also ask my son to verify if the allarm is working. May be the car is sensing something when it stop cranking but the siren is not working.

I appreciate you taking the time to point out not to take the car to neither MB nor FCA dealers. In my life i have always avoid dealers as much as possible. in my experience they not rarelly replace working parts for fun and charge you plenty :-)

Thanks!
Salvo