**Blender Version**
Broken: blender-3.0.0-beta+v30.11392829adfe-windows.amd64-release is when the problem started
Worked: blender-3.0.0-beta+v30.348d7c35a9f9-windows.amd64-release
Create two curves and put them into Join Geometry. Add two Attribute Capture nodes after one of the curves, one set to Point and one set to Spline. Now most blender actions will create a crash (changing slider values for example). If both are Point or both Spline it doesn't happen.
Opening the attached file may make it crash, if not, dragging sliders in the modifier panel will do it almost instantly.
{F11729462}
{F11729482}
{F11729493}