Adjusting Ikea Godmorgon drawers

I have the following washbasin cabinet Godmorgon 799.030.44, everything is fine so far except that adjusting the drawers simply does not work, on the sides I still have a gap at the top, I have already fully extended the adjustment screw, it can't go any further, but the gap remains! Can anyone help????? Up and down as well as left and right are no problem, but on the side it is not flush.... Where is the mistake?

A gap of about 2 mm is normal. Does the rubber buffer glued on the front not rest against the body?

For the drawers, the gap at the top is about 8mm and at the bottom maybe 1mm, creating a gap triangle. I haven't glued the rubber buffers on yet!!! The instructions say that you adjust these gaps at the little wheel at the back of the rails..... but honestly? Not much happens...... there must be some trick somewhere or I'm missing something..... don't know what else to do

To me, it reads as if the drawer is not properly inserted. Are the prongs of the rails at the back plugged into the holes of the drawer?

hm, no, that actually can't be, unfortunately I can't look there, I'll just take a mirror and check it out! but I think they are already inside, otherwise the drawer wouldn't close at all!!!!

....so I went home, put the lamp and mirror in the closet, and behold, you were RIGHT, the checkmarks were not properly in place and behold now it actually worked...... THANK YOU you saved my day!!!!