I have a graph panel in which two data rows are displayed. The values are always either 0 or 1, the y-axis is configured not to show the 0-values, because I am only interested if at a certain timestamp value 1 or value 2 is 1. Grafana displays these values correctly next to each other (1) or incorrectly below each other (2) depending on the selected time period.
If you hover over the apparently invalid points what does it say the value is?
If you set the scaling to auto what do you see?
What query have you specified? For example, if you have used mean() then it will average values over the pixel interval which can give intermediate values of course.