Problem in adding vias during differential pair routing

Upon trying to route differential pair, if routing in straight traces from the pads, can't place via during routing. Vias can be added only after bending traces. Upon modifying the DP (trace width and spacing) configuration in the netclass, there is no problem. I can't see why current configuration has issue.

Description

Attached is ZIP file contains test project. TestPCB.zip

Steps to reproduce

1. Select differential pair pads to route from
2. Press "6" to begin routing
3. Pulling traces straight a bit
4. Press "v" to place vias
5. Observe that vias can't be placed
6. Bend the traces - vias can be placed

KiCad Version

Application: KiCad (64-bit)

Version: (6.0.0-rc1-400-gd1e6c216e1), release build

Libraries:
	wxWidgets 3.1.5
	libcurl/7.78.0-DEV Schannel zlib/1.2.11

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

Build Info:
	Date: Dec 11 2021 09:00:14
	wxWidgets: 3.1.5 (wchar_t,wx containers)
	Boost: 1.76.0
	OCC: 7.5.0
	Curl: 7.78.0-DEV
	ngspice: 35
	Compiler: Visual C++ 1929 without C++ ABI

Build settings:
	KICAD_USE_OCC=ON
	KICAD_SPICE=ON