Florin, I feel with you!
Just today, I had yet another issue (in addition to the issues with the "NO FF CREDIT and the "NO FARE" as presented in another post) in CDG in which my connecting flight from CDG was operated by AF. Although being a ST Elite Plus, my original BP printed by DL showed no evidence of that and the reprint by AF did not either. Only my SM# was on there with a "FT" in front of it.
The result: no preferred seating, no n°1 access, no priority baggage - no nothing. Best thing is always to try and discuss with the AF gound staff that is perfectly qualified to speak English and really enjoys dealing with non-French passengers.
Another job well done by that joke of an alliance.