The values on the graph differ from the real ones

I am using Grafana 8.5 to display signal processing results in my application.
For example, I need to display a signal/noise graph. This value can be either positive or negative, so I use Gauge.
I am using time series for visualisation and query like this


The problem is that the graph shows data that is about twice as large as the real data (real data is about 18-20, and about 45 on the chart).

Perhaps another query should be used?
How can I get the same values on the chart as in my application?

Hi @proso

Can you please try to reproduce this same issue on and then share the dashboard link so that we can view it (just use any dummy Data e.g. for Datasource you could use TestDB which has many dummy data to reproduce it)?