I guess Construct 2 is developed with MFC. I create a temporary project and found that bug. Also I create a 'workaround' for you =)
Border:
- Thin -> OK but no resizing :(
- Resizing -> Bug with maximize and minimize
- Dialog Frame - OK but no resizing :-(
//OnInitDialog
CMenu* pSysMenu = GetSystemMenu(FALSE);
if (pSysMenu != NULL)
{
pSysMenu->RemoveMenu(SC_MAXIMIZE, MF_BYCOMMAND);
pSysMenu->RemoveMenu(SC_MINIMIZE, MF_BYCOMMAND);
}