Ok.. I tested this.
by using different Redis Databases will solve the previous issue I mentioned.
Eg -
Website 1 - define( 'WP_REDIS_DATABASE', 0 );
Website 2 - define( 'WP_REDIS_DATABASE', 1 );
Website 3 - define( 'WP_REDIS_DATABASE', 2 );
Now when you "Flash Cache" from Website 2, the...