@enricof Did you try with just rootCAs in pemtrustedcas and intermediate with node cert in both plugins.security.ssl.transport.pemcert_filepath and plugins.security.ssl.http.pemcert_filepath?
pemtrustedcas
-----BEGIN CERTIFICATE-----
< node Root CA cert >
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
< admin Root CA cert>
-----END CERTIFICATE-----
pemcert
-----BEGIN CERTIFICATE-----
< node cert >
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
< node intermediate CA cert >
-----END CERTIFICATE-----