Executed as user: Domain\machinname$. Login failed for user 'Domain\machinname$'. [SQLSTATE 28000] (Error 18456). The step failed

Here is the scenario: I'm doing migrate from "SQL Server 2008 R2 (SP3) Express Edition" to "SQL Server 2016 (RTM) Developer Edition". After all when it comes to running a job I get this error:

Executed as user: Domain\machinname$. Login failed for user 'Domain\machinname$'. [SQLSTATE 28000] (Error 18456). The step failed.

While when I run a job's content manually, everything's good and I get the result with no problem. I did a lot of changes in terms of configuration and so on, but nothing happens. Also I tried to change SQL Server Agent account from default (NT Service\SQLSERVERAGENT) to a domain account but it doesn't allow me to do this and says:

The service did not start due to a logon failure. [0x8007042d].

Is there any idea or same experience?

My Server Authentication is already: "SQL Server and Windows Authentication mode"