Atamico, did you follow the levelling video from Creality?
it shows that levelling is done without the Vat in place ad that the bed should be set to the glass.
(this is slightly worrying as it is easy to damage the glass this way.)
it also sets the bed height wrong!
I found that having the Vat in place levels the bed to the actual zero point in the Vat and not on the glass.
this will stop you from damaging the FEP as you will be technically ramming the bed into the FEP.
(when i did this i then sent the bed to hone and watched in horror as i saw the whole Z height tower and arm flex slightly as it bottomed out!)
I'm my case I found it was necessary to add a sheet of standard paper to set my bed level correctly and am now getting much better print height tolerances.
it is always slightly lower than it should be but i can live with this.