Can’t connect to Memorystore Redis over TLS

Hello,Thanks for the plugin primo ! 😀 I rarely post threads about my problems but you seem to be very active.
I have an error connecting my wordpress website ( on GCP infrastructure ) to a GCP Memorystore Redis (v7.2).
these are my WP configurations :

define( 'WP_REDIS_HOST', 10.x.x.x ); 
define('WP_REDIS_SCHEME','tls');
define('WP_REDIS_PORT', 6378 ); 
define('WP_REDIS_PASSWORD','AUTH_STRING')); 
#This i tried out of desperation :P
define('WP_REDIS_TLS_CAINFO', '/etc/apache2/sslkey/redis-ca.pem');

ERROR :

Redis is unreachable: Error while switching to encrypted communication [tls://10.x.x.x:6378]

Redis Overview :

Do you have an idea why ? thanks in advance ^^