I can't seem to figure out why this is happening, or what to change so it doesn't.  When using the spiro spline tool, with 'triangle in' shape, 2 paths get created - the one you would expect shaped like a triangle but also another filled path that fills the original bezier pen stroke.  On the path effects dialog there are 2 tabs, which you would expect (spiro spline & power stroke), but then also a 3rd box below (that must be a linked path) that is 'fill between many'.  If I delete the 'fill between many' path from the dialog - Inkscape crashes.  If I delete it by selecting it on the canvas, it doesn't crash and removes the unwanted path.  I can also uncheck the visibility box in the dialog for the fill between many paths and that makes it invisible, but it is still there - which is undesirable.  

The only way I can get it to just draw the single spiro spline path is if I draw one, and without leaving the tool, remove the fill and draw the next.  I would love to know if there is a way to set the default preference for this tool so all the other options of the path effect can be changed as well.  I know it remembers the last settings and that is what it defaults to, but it seems to be limited to the path effect in general and not any specifics for the effect itself.  Can anyone point me in the right direction?  Thanks in advance!

Are you closing the spline perhaps? Maybe adjust the thickness then. I´m not able to recreate what you´re describing though.

No, its not closed.  It seems to be closely related the fill setting.  The initial shape gets the additional closed path added to it, but once that shape is selected and the fill is removed, the next spiro path is fine.  I don't know how to make a nifty screen grab like you did, but I'll try and show you with this screenshot.  It makes sense that the fill setting would be remembered and set as default, but why is the entire second path being created?  https://www.dropbox.com/scl/fi/yfrqpdes479eys9mlafos/Screen-Recording-2024-10-28-at-12.47.01-PM.mov?rlkey=xvvsfs4l6h9ash3l8e3p8xaqu&dl=0

I think I figured it out.  It is always the simplest explanation . . .  Before starting to draw I must have selected fill - this behavior adds the additional path and fills it in (once the shape is drawn).  Alternatively, if I select no fill before drawing, it draws just one path.  I had a time recreating the issue once it was resolved too, lol.   So inkscape was remembering the fill-added setting and each time I would use it it would add the extra path.  A bit non-intuitive to select fill or not before anything is drawn, but that is the case.  As far as the crashing goes, I'm using 1.3.2 for Mac -- the crash happens when I right click on the path within the dialog and delete it that way.  This is probably not a bug because I'm asking it to delete a linked path.  Just another nuance.  I appreciate your help!

As I said I`m not able to recreate this behaviour - perhaps go Inkscape Preferences->System and reset Preferences - restart Inkscape and check if it´s working as expected.