Ok. Got it to work !
PartTran was part of this query and one thing to avoid is looking into this table… 
Anyway the info retreived was available via the jobs tables so I removed it. I did so many changes I can’t remember which one(s) resolved the issue…
But the good news are that the query was able to run…
And it ran in less than 6 seconds…
But still… I am stunned to notice such difference between the two versions !
Thanks all for your support!
Pierre