Not appearing plain text password for MySQL

[KevinLiebergen]

I run the heralding with an Ubuntu 22.04 (jammy) through docker.

From the client side I run the following commands to connect to MySQL, with the "a" password always.
I did not try it with other protocols.

~ 
➜ mysql -h x.x.x.x -u admin -pa
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user 'admin'@'x.x.x.x' (using password: YES)

~ 
➜ mysql -h x.x.x.x -u admin -p 
Enter password: 
ERROR 1045 (28000): Access denied for user 'admin'@'x.x.x.x' (using password: YES)

~ 
➜ mysql -h x.x.x.x -u admin -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'admin'@'x.x.x.x' (using password: YES)

From the server side:

# tail -f log_auth.csv 
timestamp,auth_id,session_id,source_ip,source_port,destination_ip,destination_port,protocol,username,password,password_hash
2024-06-18 16:27:52.959029,385cad38-7e44-4599-9976-88a8b8a16bb6,f3006222-1afb-43cd-a52d-d7505ece49b3,y.y.y.y,51102,x.x.x.x,3306,mysql,admin,9290b6a4f7b5469713a898180e2d88eacc4ee5ef,
2024-06-18 16:28:09.591041,2dd1cafc-695a-469a-911e-02586991d634,707c1c38-9445-4e43-8a84-8fc31996e9d8,y.y.y.y,36258,x.x.x.x,3306,mysql,admin,a5ca872c7284ae68f25bce0de67f6558dacf617b,
2024-06-18 16:28:15.919529,880e6aef-b08a-430f-90bc-a8974914e003,cf95bd69-dc24-4e3f-aa38-3f839c7babaf,y.y.y.y,36266,x.x.x.x,3306,mysql,admin,29fc4c352c08c1df4f1c46d5ccbcde11e0cc16a7,

Here, the questions are:

1. Why, if I always write the "a" password, the hash of the password changes?
2. Why it does not appear the password plain text?