Filter Curve EQ dB slider problem

In the upper left I have the Filter Curve EQ just how I like it.

When I take the “-dB” slider down to -120dB I get the image on the upper right, which you can see has gone askew on the vertical axis.

In the bottom you can see when I slide the “-dB” back to -10 dB the curve has gone way askew on the vertical axis.

The dB slider is ostensibly useful for fine tuning. This is no bueno. Should I create and save the preset without touching the “dB” slider at all?

But then I run into another problem: when I reset Filter Curve EQ to factory default the dB slider defaults do NOT reset. This is a problem when you use different presets with different dB slider values, when you can see they go askew.

What dB slider levels should I choose BEFORE I create?

After seeing this how can I really believe the filter curve settings?

The “dB sliders” are just zoom controls so that you can see better. They have no affect on the processing.