It’s far more likely that this is just weight variation which is allowable per the Food Safety and Inspection Service
However, I would sooner blame the scale itself as it doesn’t look like a scientific scale. So it’s likely not calibrated and will drift over time. Plenty of things could explain an 8g difference as measured by the average joe.
Most kitchen scales could be easily calibrated with a measuring cup and water if they really wanted to do this. Just have a few included cups for 25,50,100ml of water and then fill them on the scale and tell it what the volume is.
That will easily get you within a gram of error for most common food weights.