A couple of tips to check for scale problems
Scales, especially digital, can develop problems over time. The electronics just seem to fizzle out for no reason. Mechanical balance beam types are less prone to peter out, but still develop problems because of dirt, corrosion, or wear on the knife edge.
These problems tend to develop over long periods of time and are difficult to detect because they tend to creep up on you. But there is a very good procedure for tracking them.
The first step is to weigh an empty case of the caliber you usually reload about 10 times. Write these weights down and figure the average. Put the case and your numbers in a plastic bag and keep it for reference. This will give you a check on the high range of the balance over time. Every so often take the case out and weigh it again. The weight should fall somewhere within your average. If it does not, you need to check the scale.
The second part is to check the low range of the scale. For this cut up pieces of aluminum foil until they approximate the weight of the powder charge you use. The weight does not need to be very accurate maybe 1 or 2 grains for pistol or 5 or 10 grains for rifle. Weigh the foil and trim or add as needed to get it somewhat close to the powder charge. Then roll the foil up into a little ball so that parts don't off easy and weigh it about 10 times. Record the weights and average and put it in a plastic bag for future reference. Check your low range standard from time to time and it should fall somewhere in your standard range.
You will now have two long term standards to check your balance against and it didn't cost anything.
While I am new to reloading I am not new to weights and measurements and have a pretty good understanding of how scales work, how they can screw you up, and what you need to do keep them accurate.