Automation point disappears when moved to the same time position as another point

When two automation points have different values but are moved to exactly the same time position (same X coordinate), one of the points disappears. This happens both when dragging a point with the mouse and when moving it horizontally with the arrow keys. Steps to reproduce:

1. Create an automation point at 0 dB.

2. Create a second automation point at a lower value, for example -6 dB.

3. Move the second point towards the first point on the X axis.

4. As long as there is a very small horizontal distance between the two points, both points remain available.

5. Move the second point one final step so that both points have exactly the same time position.

6. One of the automation points immediately disappears. Because of this, it is currently not possible to create a true vertical automation step, for example:

The only workaround is to keep a tiny horizontal distance between the two points. This works, but creates a short ramp instead of an instantaneous value change. Other automation editors, for example MixMeister, allow two automation points at the same time position with different values. This makes it possible to create a vertical step while keeping both points independently editable. It would be great if Silverdaw could support the same behavior: multiple automation points may share the same time position as long as their values are different. The attached screenshot shows the closest I can place the two points without one disappearing. Moving the lower point one more step to the left, so both points have exactly the same time position, immediately removes one of them.