Hello @Juan Manuel Nieto,
The 'request is a replay' usually means that your Kerberos KDC is processing two same requests (almost) at the same time and 'thinks' that the second request is actually a replay attack than a legitimate request. Therefore it will drop the second request.
Things to check here:
1. KDC logs - try to find out for which requests and what principal, it is complaining about
2. Application log - Check YARN ATS log for any possible error w.r.t. Kerberos
3. Are you using same keytab with multiple services? (apart from spnego.service.keytab which is shared across services on a node). If yes, please try and use different keytabs for different services.
For the logs, it'll be worth to increase the Kerberos debug level by setting up "-Dsun.security.krb5.debug=true" in the JVM parameters and also try 'export KRB5_TRACE=/tmp/somefile' on the client-side before running a curl request (using browser won't help much).
Hope this helps !