Changing spline connection in inspector causes splines to revert to defaults

[lacota]

I've had this happen a number of times now. While working with spline connection properties in the inspector suddenly all splines lose their connections and revert back to default settings. All positions and rotations are lost and each spline becomes a loop. No error messages in the debug panel. Huge amount of work completely lost. Undo doesn't restore anything.

Note: This just happened when splitting a spline so nothing to do with connections.

Followup: Recreated all my splines and turned them into prefabs and so far no recurrence of the reset.