Hello,
If you did an oil change then most likely there is a small amount of oil left in the fork which will add to the total volume measure when refilling the fork. It is best to set the oil hieght when I fork has had oil in it.
You can measure the oil hieght and get a better measurement.
Check your oil hieght;
Remove the top caps and spring and measure the oil hieght. It should be 65-70mm from the top of the stanchion.
If you do this you will be able to get full travel and have a more accurate setting.