DC sweep, sweeping 2 sources just shows a single graph

Description

A user has provided this report (https://forum.kicad.info/t/simulation-dc-sweep-sweeping-2-sources-just-shows-one-graph/48836/1): simulating a dc sweep with V1 varied and R1 varied, and plotting i(R1) does show only a single graph (of the final R1 value). Plot to be expected (standard ngspice) Current plot Eeschema Printing the data does show that ngspice is delivering all data correctly.

Project attached: DC_V_R.7z

Steps to reproduce

1. Run the simulation of the project attached.

KiCad Version

Application: KiCad Schematic Editor x64 on x64

Version: 8.0.0, release build

Libraries:
	wxWidgets 3.2.4
	FreeType 2.12.1
	HarfBuzz 8.3.0
	FontConfig 2.14.2
	libcurl/8.5.0-DEV Schannel zlib/1.3

Platform: Windows 10 (build 19045), 64-bit edition, 64 bit, Little endian, wxMSW

Build Info:
	Date: Feb 23 2024 02:24:15
	wxWidgets: 3.2.4 (wchar_t,wx containers)
	Boost: 1.83.0
	OCC: 7.7.1
	Curl: 8.5.0-DEV
	ngspice: 42
	Compiler: Visual C++ 1936 without C++ ABI

Build settings: