Opensearch security plugin with certificate chain

Hi Pablo,
it works with an admin cert signed by the same Intermediate/RootCA as the node cert.
It does not work if the admin cert is signed by a different CA, even if I add the admin cert CA to the .pem file as value of *.pemtrustedcas_filepath as you suggested, such as:

-----BEGIN CERTIFICATE-----
< node intermediate CA cert> 
-----END CERTIFICATE----- 
-----BEGIN CERTIFICATE-----
< node Root CA cert > 
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
< admin Root CA cert> 
-----END CERTIFICATE-----

I tried also the reverse order with no success.
Do you have any idea?
Thanks for your help.