Why does Basic MsgBox MB_YESNOCANCEL + MB_DEFBUTTON2 give the 3rd button as the default

MsgBox(“hello”, MB_YESNOCANCEL + MB_DEFBUTTON2)
gives the 3rd ( Cancel) button as the default instead of the 2nd (No) button.
Why is this?
This is on Ubuntu.

Bildschirmfoto von 2025-05-11 20-31-24
Version: 25.2.3.1 (X86_64) / LibreOffice Community
Build ID: d8d1af5f77df955194e52baabe19324532ac8e8b
CPU threads: 4; OS: Linux 5.15; UI render: Skia/Raster; VCL: x11
Locale: de-DE (de_DE.UTF-8); UI: en-US
Calc: threaded

Pasted image

Sorry, the default Ubuntu screen shot grabber un-highlights the selected button, but it IS Cancel.

Version: 24.2.7.2 (X86_64) / LibreOffice Community
Build ID: 420(Build:2)
CPU threads: 4; OS: Linux 6.11; UI render: default; VCL: gtk3
Locale: en-GB (en_GB.UTF-8); UI: en-GB
Ubuntu package version: 4:24.2.7-0ubuntu0.24.04.4
Calc: threaded

tdf#164736

The dialog style is one of several reasons why I start LibreOffice on Ubuntu with

SAL_USE_VCLPLUGIN=gen libreoffice25.2

GTK does not work perfectly well with LibreOffice.