Tank content vs. tank indicator

Servus, have since the end of Feb. 19 my Leon ST FR 1.4 110KW. Have for a long time the feeling that partly the tank content does not match the tank indicator. Yesterday I refueled 23l and the tank indicator showed before the tanking 3/4 full. With a 50l tank that does not fit!! The emptyer the tank however the better fits the tank content to the tank indicator!?! The residual range in the BC seems to be consistent however. Last 500km driven, tank indicator at 1/2 full and residual range BC 290km! ?! Is that normal with Leon? With my previous exeo, this fit in about and also with the previous vehicles I do not know such a behavior of the tank indicator.