That sounds more like a contaminated strip rather than a good reading.
And yes, it's a feature that we all "enjoy".
To address it takes a combination of care in management of the strips and care in management of the tests.
Keep the strips in their container until needed. Keep the container in a dry room temperature environment. Close the container as soon as you've taken the strip out. Make sure your hands are clean and dry and don't allow the strip to rub against your skin on its way to the blood drop.
Our meters have a quality control system that permits an up to 20% error, so you could well get two readings within minutes of one another, one of 100, and the next at 120 and both would be "right"
Given their cost, I have to say that I'm disappointed that these guys don't do better!