I told you exactly how to replicate the problem. It behaves the same on both my personal Win10 22H2 computer and work computer with Win10 21H2, which definitely has potential to have installed multiple interfering software packages, beginning from different group policy settings, up to corporate other monitoring and antivirus software. My personal computer is almost fresh install of Win10, so I seriously doubt it is a problem of other software interfering.
Content of the RC file is below, I see absolutely no issue there. It even compiles fine in an ancient version of Pelles C.
// RESOURCE SCRIPT generated by "Pelles C for Windows, version 12.00".
#include <windows.h>
#include <commctrl.h>
#include <richedit.h>
#include "resource.h"
LANGUAGE LANG_ENGLISH,SUBLANG_ENGLISH_US
DLG_MAIN DIALOGEX DISCARDABLE 6, 18, 210, 142
STYLE DS_SHELLFONT|WS_POPUP|DS_MODALFRAME|DS_CONTEXTHELP|DS_3DLOOK|WS_CAPTION|WS_SYSMENU|WS_VISIBLE
CAPTION "Dialog"
FONT 8, "Tahoma", 0, 0, 1
{
CONTROL "OK", IDOK, "Button", WS_TABSTOP, 160, 5, 45, 15
CONTROL "Cancel", IDCANCEL, "Button", WS_TABSTOP, 160, 23, 45, 15
}
In the resource.h file, there is just the one expected #define:
#define DLG_MAIN 1001
I can only think of Pelles IDE could have possible trouble with the Windows OS being localized for different, than US/English. (Meaning, for example we do not use decimal point but comma instead, etc).