From how you describe your problem I would think you would have the same outcome on a balance beam scale.
You have to load the scale at very near the same rate each time.
When I recheck loads I always have to spill the powder back onto the scale very slowly.
Maybe the electronic scales are even more touchy?
For the message of the Cross is foolishness to those who are perishing, But to us who are being saved, It Is The Power Of God. 1Corinthians 1-18