Hello all, thanks a lot for your inputs. Actually, I've followed the last "exercise" suggested by Sesquitone, and it does appear that my feeling of the low register was wrong. I tried to play a D3 on 6th position with the G-att engaged and I obtained a slightly low Eb instead. Had to lower the position for a proper D. I repeated the scheme down an octave and you guys are right, I do have to lower the positions to obtain good pedals, and therefore, have no more Db2 !
Concerning the valve, it's perfectly adjusted so I won't blame the equipment, but only myself
Here a "proof" that the G-att length is perfect for the D3, down to B2 ( sorry for the tone, I was picking the horn cold)
https://youtube.com/shorts/wQzIwok9HI0? ... Elrm8a32nG
Thank you all for your help
