Setting teardrops after filling saves file differently. prefer_zone_connections attribute keeps changing.

Description

If "Prefer zone connection" setting is on, prefer_zone_connections is dissapers from the file after setting teardrops and saving.

Filling and clearing zone fills brings the prefer_zone_connections attribute back after saving the file!

Here is a demonstration: https://github.com/Springer-Electronics/kicad-test/commits/main/

If "Prefer zone connection" setting is off, prefer_zone_connections shows up in the file after setting teardrops and saving. This seems opposite to what should be happening, but I am not sure.

Steps to reproduce

1. Add zones, fill (B), clear (ctrl+B),
2. Save the file
3. Make sure "Prefer zone connection" properties are On for the teardrops, and Edit / Edit teardrop / OK
4. Save the file with new name
5. Compare the files and notice multiple prefer_zone_connections is missing in the file

KiCad Version

Application: KiCad PCB Editor x64 on x64

Version: 7.99.0-3969-gc5ac2337e4, release build

Libraries:
	wxWidgets 3.2.4
	FreeType 2.12.1
	HarfBuzz 8.2.1
	FontConfig 2.14.2

Platform: Windows 11 (build 22631), 64-bit edition, 64 bit, Little endian, wxMSW

	wxWidgets: 3.2.4 (wchar_t,wx containers)
	Boost: 1.83.0
	OCC: 7.7.1
	Curl: 8.4.0-DEV
	ngspice: 41
	Compiler: Visual C++ 1936 without C++ ABI

Build settings: