Duplicate items error during annotation after importing an Altium Project

Problem description

This reports the problem explained in the first post of this thread: https://forum.kicad.info/t/duplicate-items-error-during-annotation-after-importing-an-altium-project/66542

Steps to reproduce

  1. Import the Altium designer project
  2. auto-match PCB layers
  3. in schematics, press F8, and try to run annotation process
  4. results in "duplicate items" errors which is a blocker for the "forward annotation to PCB" flow

KiCad Version 

Application: KiCad x64 on x64

Version: 9.0.7, release build

Libraries:
	wxWidgets 3.2.8
	FreeType 2.13.3
	HarfBuzz 12.2.0
	FontConfig 2.15.0

Platform: Windows 11 (build 26200), 64-bit edition, 64 bit, Little endian, wxMSW

	wxWidgets: 3.2.8 (wchar_t,wx containers)
	Boost: 1.89.0
	OCC: 7.9.2
	Curl: 8.17.0-DEV
	ngspice: 45.2
	Compiler: Visual C++ 1944 without C++ ABI
	KICAD_IPC_API=ON

Locale: 
	Lang: en_AT
	Enc: UTF-8
	Num: 1.234,5
	Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)
Edited by patzf