SQL Server account locked out and password did not match?

It looks like your SQL Server account is experiencing two distinct login failures:

Account Locked Out: This suggests multiple failed login attempts within a short period, triggering the account lockout policy.

Incorrect Password: This indicates that something is attempting to authenticate using an outdated or incorrect password.

Since you’ve already checked SQL Agent jobs, linked servers, Windows services, and Task Scheduler, here are a few more areas to investigate:

Check Active Directory (If Using Windows Authentication)

If the account is an AD user, check the lockout policy and review AD logs for failed login attempts.

Unlock the account in AD if needed (Active Directory Users & Computers → Find User → Properties → Account Tab).

Check SQL Server Logs in Detail

For example this query may help:

SELECT login_time, host_name, program_name, login_name FROM sys.dm_exec_sessions WHERE login_name = 'sql_account_name'

Also check error log with this sql query:

EXEC xp_readerrorlog 0, 1, N'Login failed'

And you can maybe audit/check running applications. 

There might be an application, script, or process running under this account with an outdated password.

Check connection strings in web.config/app.config files if this account is used in applications.