I have occasionally run into a problem in Inkscape where I am trying to join two nodes that are snapped on top of each other in order to combine curves, but doing so alters the curve type of one of the joined curves.
For example, I have two curves here
But when I join the two overlapping nodes at the right angle, the lines in the round curve become "rigid", and I don't know how to prevent or modify this behavior.
Is there a way to stop this behavior? Here is an example file with the problem