C# Convert.Frombase64string returns different from PHP base64_decode

Question

I’m doing the Decode in c# of a Base64 to be able to generate a Qrcode, in PHP it works normal but in c# the return of the Decode is different. This Base64 is created and encrypted by Serpro and they ask to do the Decode of Base64 and with the byte[] that returns from the Code generate a Qrcode. PHP code working normal:

<?php  
include('C:\php\lib\phpqrcode\qrlib.php');
    $file = 'D:\Teste\qrcode.png';
    $a = base64_decode('X0gJQwUAEQBGMEQCIFFztpz6Yi2OHOR9QafHjL4y8MtlwHG7fgE9q9KycCBXAiBlU+xqMnYHBdpArpgxZee/PvsqO5BmEyvAdqSFtLzCNgAAAAxJBBhFVBJBlhBVlAA=');
    QRcode::png($a, $file,  QR_ECLEVEL_M, 3, 1);
?>

In php returns this correct Qrcode, validated by Serpro!

Code in c# with different code

// Dll MessagingToolkit.QRCode
string stringBase64Endode = "X0gJQwUAEQBGMEQCIFFztpz6Yi2OHOR9QafHjL4y8MtlwHG7fgE9q9KycCBXAiBlU+xqMnYHBdpArpgxZee/PvsqO5BmEyvAdqSFtLzCNgAAAAxJBBhFVBJBlhBVlAA=";
string textoDecode = Encoding.UTF8.GetString(Convert.FromBase64String(stringBase64Endode));

var qrCode = new QRCodeEncoder();
qrCode.QRCodeBackgroundColor = Color.White;
qrCode.QRCodeForegroundColor = Color.Black;
qrCode.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
qrCode.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.Q;
qrCode.QRCodeScale = 2;
var resultado = qrCode.Encode(textoDecode);
resultado.Save("D:\Teste\qrcode.png");

In c# returns this incorrect Qrcode, not validated by Serpro!

How do I make Encoding.UTF8.Getstring(Convert.Frombase64string()) in c# return the same result as base64_decode in php?