It's alright! Now my bromoils are flawless... (so to speak )
Problem disappears if I rock costantly the tray with the print inside before inking it. I've also "super-dryed" the bleached print with an hair dryer before soaking into water (some of my sources mentioned this possibility to improve ink adhesion). I also added some sodium carbonate to the fixer after the bleaching bath to make it more alkaline.
Combining those things togheter makes the inking smooth and easy... Much quicker too!
Keeping an eye on the tray and rocking the tray is very boring, but with my papers only 10 minutes of soaking are needed.