Creality Ender 3 V3 SE print problems

I unboxed the printer and assembled as per instructions, fitted some PLA filament, did the auto bed levelling sequence selected an article to print and first off the board was perfect, same for the next 12 prints of small items then nothing would stick to the bed. Washed the PEI plate in hot soapy water, no change, used hair spray, no change, found the Creality eb page on how to setup the slider etc (https://www.youtube.com/watch?v=iaExzAYR_Fo), no change. Then I started to wonder WHY it printed 14 items out of the box, si I figured that maybe some screws were coming loose because of the vibration when printing fill in stuff. So I basically dismantled every part and re-assembled them all making sure screws were tight but not tight enough to distort parts, Paid particular attention to the plastic NUTS that follow the Z axis screws, I found the bolts stripped in the plastic so I use slightly longer bolts and fitten on M3 nuts. After finally levelling every thing and doing an auto level again it came up all GREEN squares like it did when first used. The ONLY other item I use now is a product called “FILAFORM 3D Printer Spray” Made in Australia , a little pricey but absolutely NO more adhesion problems now. I can print a 1 kg roll of filament without a hiccup, just follow the instructions of the FILAFORM…