Rocket fuel tanks continue filling past set capacities if the rocket has launched and returned since the capacity was set.
Steps to Reproduce
I set a liquid rocket fuel tank to fill (with petroleum) to some amount (e.g. 200 kg) less than its total capacity (900 kg). It fills correctly to 200 kg, and I launch the rocket. When the rocket returns, the tank begins refilling. Although it still has the same set capacity, it continues filling past that number to its total capacity of 900 kg. Setting the desired capacity again causes the tank to stop filling, and a duplicate will eventually come to remove the excess fuel in bottles.
This issue has not been confirmed by a developer yet.