eeschema: various bugs and crash while editing connections

Description

Various problems while editing connections and placing parts on existing connections. Connection dots are missing, connection dots are flickering during editing, connections get lost during editing, crash during editing of connections.

It does not depend on the project. I have tested it.

All of the above points have worked before. From which version on it does not work I could not tell you.

Steps to reproduce

Description of the video attached

1. drew a connection, connection dot is missing
2. copied a component by the usual short-keys and placed on an existing connection, connection below has vanished, the same happens for horizontal placed components, then the right connection gets lost (it seems there has to be another connection dot or a component in line on that connection to get lost)
3. editing connections (only left mouse button was used) with crash at the end

1-2025-08-19_14.06.09

KiCad Version

Application: KiCad Schematic Editor x86_64 on x86_64

Version: 9.99.0-unknown-a0940b10d4~186~ubuntu24.04.1, release build

Libraries:
	wxWidgets 3.2.6
	FreeType 2.13.2
	HarfBuzz 8.3.0
	FontConfig 2.15.0

Platform: Ubuntu 24.04.3 LTS, 64 bit, Little endian, wxGTK, X11, cinnamon, x11
OpenGL: AMD, AMD Radeon RX 5600 XT (radeonsi, navi10, LLVM 19.1.7, DRM 3.57, 6.8.0-47-generic), 4.6 (Compatibility Profile) Mesa 25.1.7 - kisak-mesa PPA

	wxWidgets: 3.2.4 (wchar_t,wx containers) GTK+ 3.24
	Boost: 1.83.0
	OCC: 7.6.3
	Curl: 8.5.0
	ngspice: 43
	Compiler: GCC 13.3.0 with C++ ABI 1018
	KICAD_IPC_API=ON
	KICAD_USE_PCH=OFF

Locale: 
	Lang: de_DE
	Enc: UTF-8
	Num: 1.234,5
	Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)