Error Compute Signature VB2022 #341

VB.net 2022:

I try to sign an XML but with an URI = Id whose value is numerical.
But "compute Signature" will not sign and generates an error:
System.Security.Cryptography.CryptographicException: Malformed reference element.
Certificado = New X509Certificate2(_CertArchivo, _CertContrasenia, X509KeyStorageFlags.Exportable)

  xdTmp = New XmlDocument With {

.PreserveWhitespace = False
}

  xdTmp.Load(xmlAFirmar)

sxTmp = New SignedXml(xdTmp) With {
.SigningKey = Certificado.GetRSAPrivateKey
}
sxTmp.SignedInfo.SignatureMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"
sxTmp.SignedInfo.CanonicalizationMethod = "http://www.w3.org/TR/2001/REC-xml-c14n-20010315"

    Dim ReferenceId As String = FindReferenceId(xdTmp)........'Call Function ReferenceID'
  
  refTmp = New Reference With {
         .Uri = "#" & ReferenceId
  }
 
  refTmp.AddTransform(New XmlDsigEnvelopedSignatureTransform)

refTmp.AddTransform(New XmlDsigC14NWithCommentsTransform)

sxTmp.AddReference(refTmp)

  sxTmp.ComputeSignature()