I have always noticed this on all my cars. I would hear the pop and I can put in almost 5 more liters. It depends on a few things to be honest, if there is no one else using pumps then you will notice it will fill a lot faster making a lot of bubbles and causing the pump to click off. Just like head on a beer it will settle and you still have tons of room. Next is the neck to your tank it can cause bubbles depending on how fast etc.. On my CX-5 I have the 56 liter tank and I know when my tank reads empty (no marks on the gauge) I can put in 50 liters. If I am at 1/4 tank left, then I know I can put in 40 liters. based on that I am never really trying to over fill it to the point I can see gas sitting at the top but I can tell if it click off at 40 liters and I could put 50 in it then I know I can go more if I let the bubble settle.
Get to know your tank and understand how much fuel it holds based on the fuel gauge and you will know how many liters it should require to fill.