Cause :
The resize does not work for the bezier line as it is fundamentally different than a classic geometry graphic with simple width, height, x and y. A line can't be resized by default, it's disabled. But due to the blueprint being in a frame the line is now a child of the frame, so it's affected by the resize of the frame.
How to solve :
Implement a resize support for the line.
Cause :
The resize does not work for the bezier line as it is fundamentally different than a classic geometry graphic with simple width, height, x and y. A line can't be resized by default, it's disabled. But due to the blueprint being in a frame the line is now a child of the frame, so it's affected by the resize of the frame.
How to solve :
Implement a resize support for the line.