WE 1911 - grip safety causing blowback problem?

[sewktbk]

hey guys, i posted this in the Doctor's section but didn't get anything relevant, and since it happened while i was repainting my gun, i figured it could belong here too :

alright so i completely disassembled my WE 1911 for a repaint job. i reassembled it a few times during the process and tried it out, not a single problem, still worked like new.

Now when I finished the paint job (slide only), i reassembled it, and the gun acts weird. When i shoot, the slide blows back, but not entirely, and the gas discharge is weak. However when i release the grip safety half way (meaning i don't tightly hold the handle) the gun shoots perfectly fine, full throttle, very good and normal recoil.

What adjustment do i have to make? how come the grip safety influences the good function of the blowback?

Edit : i tried adjusting the leaf spring and it got a little better, but still not resolved. I'm guessing is the prongs that have to be bent a certain precise way? am i in the right direction? how could this adjustment suddenly fail, since i haven't altered anything?

help me out if you can, or even have a slight idea of what it might be, greatly appreciated.