fft not working (Error: fft needs real time scale)

I'm trying to use fft but it's not working. Transient simulation looks good but when I try fft I get the error: Error: fft needs real time scale

Schematic attached: mix_spicesim1.kicad_sch To reproduce:

1. open the schematic
2. do transient simulation with parameters: time step 1p, final time 100n, compatibility Spice; then display V(if)
3. Try FFT of V(if)

Diode model under the link below (although fft fails even without the diodes) https://www.infineon.com/cms/en/product/rf/rf-diode/rf-mixer-and-detector-schottky-diode/bat15-03w/#!?fileId=db3a304313d846880113def7762004aa

Application: KiCad x86_64 on x86_64

Version: 7.99.0-unknown-d8be69c3c1~174~ubuntu22.04.1, release build

Libraries:
	wxWidgets 3.2.1
	FreeType 2.11.1
	HarfBuzz 2.7.4
	FontConfig 2.13.1
	libcurl/7.81.0 OpenSSL/3.0.2 zlib/1.2.11 brotli/1.0.9 zstd/1.4.8 libidn2/2.3.2 libpsl/0.21.0 (+libidn2/2.3.2) libssh/0.9.6/openssl/zlib nghttp2/1.43.0 librtmp/2.3 OpenLDAP/2.5.16

Platform: Linux Mint 21.2, 64 bit, Little endian, wxGTK, X11, mate, x11

Build Info:
	Date: Oct 31 2023 20:10:08
	wxWidgets: 3.2.1 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.74.0
	OCC: 7.5.2
	Curl: 7.81.0
	ngspice: 40
	Compiler: GCC 11.4.0 with C++ ABI 1016

Build settings: