2D Blendspace breaks when aligning samples in a straight line

2D Blendspace breaks when aligning samples in a straight line

Regression: YES

Worked: 3249277 (4.14.3)
Broken: 3299760 (4.15.0)

1. Create a third person template project
2. Create a Blendspace (2D)
3. Add 5 animation samples in a straight horizontal line across the graph
4. Hold Shift and move the preview around

Result: From center to the right side, the samples don't work
Expected: Entire graph works properly