Validation d'un pdf signé par certificat

hello

On a same w10 machine, I have got a different behaviour between  Acrobat Standard and Reader DC when validating digital signature

KO under Acrobat Standard --> trust chain issue, signature not validated

OK under Reader DC

"internal PKI , intermediates and root certifcates loaded, adobe signature preferences are set OK"

still KO, help!

thanks in advance

BR