MariaDB Logging and old password support

For old password compatibility, do

SET GLOBAL old_passwords = 1;
SET PASSWORD FOR 'repl'@'%' = PASSWORD('the_password');
SET GLOBAL old_passwords = 0;

We can also try SET GLOBAL secure_auth=OFF; however I found this made no difference when running MariaDB 10.5 and attempting to connect with an old (presumable 4.1) client.

MariaDB GTID position reset

On Master, do SELECT @@gtid_current_pos;
then on Slave, do SET GLOBAL gtid_slave_pos = 'GTID_FROM_SERVER_1';

if need be do;

CHANGE MASTER TO
  MASTER_HOST='server1',
  MASTER_USER='replica_user',
  MASTER_PASSWORD='password',
  MASTER_USE_GTID=slave_pos;

then;

Start Slave;

SHOW SLAVE STATUS/G;

A note on the above, do it quickly, in case the position changes.

SELECT @@gtid_slave_pos, @@gtid_current_pos; should show the same.