Issue with Form Win/Linux

Hello,
Attached you can see 2 images of the same form running in Ubuntu Linux 18.04 (Python 3.6.5-wxPython 4.0.6) and the other in Windows 10 (Python 3.7 - wxPython 4.0.6) its exactly the SAME code, but like you can see in Windows the widgets looks not aligned and the size of the form not enough wide.

Im attaching the code of that form (not runnable sorry) This will be a huge project, I work and code all the time in Ubuntu but this program need to work in both OS, any ideas? Thanks!

CODE:

###########################################################################

Class frmLogin

###########################################################################

class frmLogin ( wx.Dialog ):

def __init__( self, parent ):
	wx.Dialog.__init__ ( self, parent, id = wx.ID_ANY, title = u"Velantur :: Acceso al Sistema", pos = wx.DefaultPosition, size = wx.Size( 288,171 ), style = wx.DEFAULT_DIALOG_STYLE )

	self.SetSizeHints( wx.DefaultSize, wx.DefaultSize )

	bSizer1 = wx.BoxSizer( wx.VERTICAL )

	self.m_panel2 = wx.Panel( self, wx.ID_ANY, wx.DefaultPosition, wx.DefaultSize, wx.TAB_TRAVERSAL )
	bSizer1.Add( self.m_panel2, 1, wx.ALL|wx.ALIGN_CENTER_HORIZONTAL, 5 )

	fgSizer149 = wx.FlexGridSizer( 0, 2, 0, 0 )
	fgSizer149.SetFlexibleDirection( wx.BOTH )
	fgSizer149.SetNonFlexibleGrowMode( wx.FLEX_GROWMODE_SPECIFIED )

	self.m_bitmap8 = wx.StaticBitmap( self, wx.ID_ANY, wx.Bitmap( "images/login.png", wx.BITMAP_TYPE_ANY ), wx.DefaultPosition, wx.DefaultSize, 0 )
	fgSizer149.Add( self.m_bitmap8, 0, wx.ALIGN_CENTER_HORIZONTAL|wx.ALL, 5 )

	fgSizer1 = wx.FlexGridSizer( 3, 2, 0, 0 )
	fgSizer1.SetFlexibleDirection( wx.BOTH )
	fgSizer1.SetNonFlexibleGrowMode( wx.FLEX_GROWMODE_SPECIFIED )

	self.m_staticText4 = wx.StaticText( self, wx.ID_ANY, u"Usuario", wx.DefaultPosition, wx.DefaultSize, 0 )
	self.m_staticText4.Wrap( -1 )

	fgSizer1.Add( self.m_staticText4, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL|wx.ALIGN_RIGHT, 5 )

	self.txtUser = wx.TextCtrl( self, wx.ID_ANY, wx.EmptyString, wx.DefaultPosition, wx.DefaultSize, 0 )
	self.txtUser.SetMaxLength( 8 )
	fgSizer1.Add( self.txtUser, 0, wx.ALL, 5 )

	self.m_staticText5 = wx.StaticText( self, wx.ID_ANY, u"ContraseƱa", wx.DefaultPosition, wx.DefaultSize, 0 )
	self.m_staticText5.Wrap( -1 )

	fgSizer1.Add( self.m_staticText5, 0, wx.ALL|wx.ALIGN_CENTER_VERTICAL|wx.ALIGN_RIGHT, 5 )

	self.txtPass = wx.TextCtrl( self, wx.ID_ANY, wx.EmptyString, wx.DefaultPosition, wx.DefaultSize, wx.TE_PASSWORD )
	self.txtPass.SetMaxLength( 8 )
	fgSizer1.Add( self.txtPass, 0, wx.ALL, 5 )

	self.btnOk = wx.Button( self, wx.ID_ANY, u"Aceptar", wx.DefaultPosition, wx.DefaultSize, 0 )

	self.btnOk.SetDefault()
	self.btnOk.SetToolTip( u"Ingresar" )

	fgSizer1.Add( self.btnOk, 0, wx.ALL, 5 )

	self.btnSalir = wx.Button( self, wx.ID_ANY, u"Salir", wx.DefaultPosition, wx.DefaultSize, 0 )
	self.btnSalir.SetToolTip( u"Salir" )

	fgSizer1.Add( self.btnSalir, 0, wx.ALL, 5 )


	fgSizer149.Add( fgSizer1, 1, wx.EXPAND, 5 )


	bSizer1.Add( fgSizer149, 1, wx.EXPAND, 5 )


	self.SetSizer( bSizer1 )
	self.Layout()

	self.Centre( wx.BOTH )

	# Connect Events
	self.btnOk.Bind( wx.EVT_BUTTON, self.btnOkOnButtonClick )
	self.btnSalir.Bind( wx.EVT_BUTTON, self.btnSalirOnButtonClick )

def __del__( self ):
	pass


# Virtual event handlers, overide them in your derived class
def btnOkOnButtonClick( self, event ):
	event.Skip()

def btnSalirOnButtonClick( self, event ):
	event.Skip()

vlinux vwin

Try removing the self.SetSizeHints() and adding a self.Fit() after the self.SetSizer(...). After that the self.Layout() may be redundant so you can probably remove that too.