Keycloak adds escape characters in signature and certificate using SAML

I am trying to set up Keycloak as IdP and use it for SSO. The first re-direct (from the application login url to keycloak) works fine, but then, after entering the user credentials I get an "invalid signature" error from the application.

I have checked the SAML response (from keycloak to the application) and I can see that keycloak adds a weird escape character in the certificate and signature value.

Here is part of the SAML response

<dsig:Signature xmlns:dsig="http://www.w3.org/2000/09/xmldsig#">
    <dsig:SignedInfo>
      <dsig:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
      <dsig:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256" />
      <dsig:Reference URI="#ID_fde25c3e-6958-4b49-bbe0-e4aeb200de98">
        <dsig:Transforms>
          <dsig:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
          <dsig:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /></dsig:Transforms>
        <dsig:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" />
        <dsig:DigestValue>p3ldrwhvbO1zoeHlhCx9TdZ01hGnw3f3IqBDIT5e1oU=</dsig:DigestValue>
      </dsig:Reference>
    </dsig:SignedInfo>
    <dsig:SignatureValue>
iGNKaLxr3c9CUPpRxC3xeS0grx2FdcXWcWArlqZHdWIjQF0n9Whh5ue00HEmb+Nr5VO9jBUwRwXl&#13; VNEARy/4DeAsuXIxej0OYASBMjx+5qfmUIelXKLChTYjrdHyq2ZtD7BWfCrnNLtB7XiZsy8cYm0v&#13; ynWLlJTyxUpg+FakcxGNDnSUG6Ofslv6byQDsNY56yvqKCWbcqa1/70PD401E/Gf2XcD4paPAvHX&#13; B+wS25QFytqrxumRtlJiKcPS+IB8umpcHG4mKk3Qg9FxCRQk2Pk693VnEtYyQ5VXUTNFW8SfWpnQ&#13;
      xDNSE6h2cevj4nT7NSQDxoNh1LRBokwjUNJWQg==
    
</dsig:SignatureValue>

Why does it have to truncate the signature and add the escape code? Is there a way to change this?

I am sure that this is the error that is preventing the application from reading the response.

Thank you in advance