This an approximately 21’ long curve with ~226 control points.
The curve was made from two separate curves that I joined. When I delete the control point at the join one of the end control points disappears. See screenshots.
I’m using version 7.0.20295.18003 (couple weeks old).
[edited to add titles to screenshots]
Control Point selected:
“Top” end of same Curve:
Control Point deleted:
“Top” end point disappears: