ratsnest doesn't show after importing netlist

Description

test1.net

I imported a netlist into KiCad nightly PCBNEW stand-alone and the ratsnest would not appear. Tried enabling/disabling ratsnest both globally and for selected items. Also tried changing the color/opacity of the ratsnest. No change.

However, saving and then restoring the layout caused the ratsnest to appear, after which it would also respond to the hide/unhide commands. Clicking "Rebuild Ratsnest" before "Update PCB" when importing the netlist also fixed the problem.

Steps to reproduce

1. Use File=>Import=>Netlist... to select a netlist file (attached).
2. Click "Update PCB". No ratsnest will appear.
3. Save and then restore the layout. The ratsnest will appear.

Alternate steps:

1. Use File=>Import=>Netlist... to select a netlist file (attached).
2. Click "Rebuild Ratsnest" and then "Update PCB". The ratsnest will appear.

KiCad Version

Application: Pcbnew

Version: 5.99.0-unknown-50e22de3ba~107~ubuntu20.04.1, release build

Libraries:
	wxWidgets 3.0.4
	libcurl/7.68.0 OpenSSL/1.1.1f zlib/1.2.11 brotli/1.0.7 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3

Platform: Linux 5.4.0-62-generic x86_64, 64 bit, Little endian, wxGTK, ubuntu, x11

Build Info:
	Date: Jan 18 2021 15:18:10
	wxWidgets: 3.0.4 (wchar_t,wx containers,compatible with 2.8) GTK+ 3.24
	Boost: 1.71.0
	OCC: 7.3.0
	Curl: 7.68.0
	ngspice: 31
	Compiler: GCC 9.3.0 with C++ ABI 1013

Build settings:
	KICAD_SCRIPTING=ON
	KICAD_SCRIPTING_MODULES=ON
	KICAD_SCRIPTING_PYTHON3=ON
	KICAD_SCRIPTING_WXPYTHON=ON
	KICAD_SCRIPTING_WXPYTHON_PHOENIX=ON
	KICAD_SCRIPTING_ACTION_MENU=ON
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON