Moving and then deleting control points breaks Tonality gradient

[FuzzyCat444]

Material Maker version: 1.3

OS/device including version: Windows 10 with GTX 1660 ti

Issue description: Editing control points in the Tonality node produces inconsistent results in the Preview2D panel, and this carries over to the Preview3D panel. Adding control points and deleting them is fine, but moving a control point and deleting it causes the gradient to permanently change. Re-selecting the Linear preset does not help. This seems to happen with the gradient node as well even though it doesn't involve a curve editor.

Steps to reproduce: Create a tonality node and select it to display Preview2D. Open the curve editor, double-click to add a control point, and move it to an extreme such as the top left corner. Right click the new control point to delete, and the gradient is altered and cannot be reversed.