PNS-router: produces tracks with clearance error

Description

With the example project and the steps below the PNS-router produces tracks which are too tight together --> resulting in clearance errors.

Steps to reproduce

1. open attached project, open schematic+board: routing_drc_clearance_error.zip
2. set track-width == 0.4mm
3. set grid == 0.127mm
4. activate bottom copper layer
5. select router walkaround mode (see picture 1)
6. start routing from U1-Pad1, and run with the new track into the existing blue track (see picture 2). commit these track.
7. run DRC, get drc-clearance errors (see picture 3)

KiCad Version

Application: KiCad PCB Editor x64 on x64

Version: 7.0.2-49-gc75672fd44, release build

Libraries:
	wxWidgets 3.2.2
	FreeType 2.12.1
	HarfBuzz 6.0.0
	FontConfig 2.14.1

Platform: Windows 10 (build 19044), 64-bit edition, 64 bit, Little endian, wxMSW

	wxWidgets: 3.2.2 (wchar_t,wx containers)
	Boost: 1.81.0
	OCC: 7.6.3
	Curl: 7.88.1-DEV
	ngspice: 40
	Compiler: Visual C++ 1934 without C++ ABI

Build settings:
	KICAD_SPICE=ON