Had a problem with my electronic scale but it turns out it was the plastic powder dump pan affecting the zero. After taking apart the powder measure of my Dillon 550 to check for problems I started to weigh loads, when the plastic dump pan was about a 1/4 inch away from the scale the digital readout would change. I rubbed the outside of the dump pan with a dryer sheet and tried again and this time no change in the readout.
Did a little static electricity cause this?