Backups in a multiserver environment while using Central Management Server and Server Groups

[tekpr00]

Hello All,
I am trying to set up backups of multiple databases a multi-server environment while using Central Management Server and Server Groups.
After I made IT-D-ADMIN2\SRVCEMNGR as my Master, in a Multi-server Administration from the SQL Server Agent, I was successful in adding and connecting 3 instances.
However, the Enlist TXS progress operation listed the following steps that the installation will take:
Create MSXOperator
Make sure the Agent service for 'IT-D-ADMIN2\SRVCEMNGR' is running
Ensure the agent startup account for 'AGV1DB' has rights to login as a target server
Enlist 'AGV1DB' into 'IT-D-ADMIN2\SRVCEMNGR'
Ensure the agent startup account for 'CMPDB' has rights to login as a target server
Enlist 'CMPDB' into 'IT-D-ADMIN2\SRVCEMNGR'
Ensure the agent startup account for 'EATECDB' has rights to login as a target server
Enlist 'EATECDB' into 'IT-D-ADMIN2\SRVCEMNGR'.

However some pass some fail with the following error. Upon Googling the error, the URL is broken:
Enlist TSX Progress
- Create MSXOperator (Success)
* Checking for an existing MSXOperator.
* Updating existing MSXOperator.
* Successfully updated MSXOperator.
- Make sure the Agent service for 'IT-D-ADMIN2\SRVCEMNGR' is running (Success)
* The service 'SQLAgent$SRVCEMNGR' is running.
- Ensure the agent startup account for 'AGV1DB' has rights to login as a target server (Error)
* Checking to see if the startup account for 'AGV1DB' already exists.
* Login 'NT Service\SQLSERVERAGENT' does not exist on server 'IT-D-ADMIN2\SRVCEMNGR'. Creating.
Messages
* Create failed for Login 'NT Service\SQLSERVERAGENT'. (Microsoft.SqlServer.Smo)
For help, click:

https://go.microsoft.com/fwlink?Pro...ExceptionText&EvtID=Create+Login&LinkId=20476

------------------------------
ADDITIONAL INFORMATION:
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
------------------------------
Windows NT user or group 'NT Service\SQLSERVERAGENT' not found. Check the name again. (Microsoft SQL Server, Error: 15401)
For help, click:

http://go.microsoft.com/fwlink?Prod...6&EvtSrc=MSSQLServer&EvtID=15401&LinkId=20476

- Enlist 'AGV1DB' into 'IT-D-ADMIN2\SRVCEMNGR' (Error)
* Enlisting target server 'AGV1DB' with master server 'IT-D-ADMIN2\SRVCEMNGR'.
* Using new enlistment method.
Messages
* MSX enlist failed for JobServer 'AGV1DB'. (Microsoft.SqlServer.Smo)
For help, click:

https://go.microsoft.com/fwlink?Pro...nText&EvtID=MSX+enlist+JobServer&LinkId=20476

------------------------------
ADDITIONAL INFORMATION:
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
------------------------------
The enlist operation failed (reason: The time-out was exceeded while the server waited for a response from SQL Server Agent. Make sure that the SQL Server Agent service is running) (Microsoft SQL Server, Error: 22026)
For help, click:

http://go.microsoft.com/fwlink?Prod...1&EvtSrc=MSSQLServer&EvtID=22026&LinkId=20476

- Ensure the agent startup account for 'CMPDB' has rights to login as a target server (Success)
* Checking to see if the startup account for 'CMPDB' already exists.
* Login exists on server.
* Checking to see if login has rights to msdb.
* Login has rights to msdb.
* Checking to see if user is a member of the TargetServersRole.
* User is a member of the TargetServersRole.
- Enlist 'CMPDB' into 'IT-D-ADMIN2\SRVCEMNGR' (Error)
* Enlisting target server 'CMPDB' with master server 'IT-D-ADMIN2\SRVCEMNGR'.
* Using new enlistment method.
Messages
* MSX enlist failed for JobServer 'CMPDB'. (Microsoft.SqlServer.Smo)
For help, click:

https://go.microsoft.com/fwlink?Pro...nText&EvtID=MSX+enlist+JobServer&LinkId=20476

------------------------------
ADDITIONAL INFORMATION:
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
------------------------------
The enlist operation failed (reason: The time-out was exceeded while the server waited for a response from SQL Server Agent. Make sure that the SQL Server Agent service is running) (Microsoft SQL Server, Error: 22026)
For help, click:

http://go.microsoft.com/fwlink?Prod...0&EvtSrc=MSSQLServer&EvtID=22026&LinkId=20476

- Ensure the agent startup account for 'EATECDB' has rights to login as a target server (Success)
* Checking to see if the startup account for 'EATECDB' already exists.
* Login exists on server.
* Checking to see if login has rights to msdb.
* Login has rights to msdb.
* Checking to see if user is a member of the TargetServersRole.
* User is a member of the TargetServersRole.
- Enlist 'EATECDB' into 'IT-D-ADMIN2\SRVCEMNGR' (Error)
* Enlisting target server 'EATECDB' with master server 'IT-D-ADMIN2\SRVCEMNGR'.
* Using new enlistment method.
Messages
* MSX enlist failed for JobServer 'EATECDB'. (Microsoft.SqlServer.Smo)
For help, click:

https://go.microsoft.com/fwlink?Pro...nText&EvtID=MSX+enlist+JobServer&LinkId=20476

------------------------------
ADDITIONAL INFORMATION:
An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
------------------------------
The enlist operation failed (reason: The time-out was exceeded while the server waited for a response from SQL Server Agent. Make sure that the SQL Server Agent service is running) (Microsoft SQL Server, Error: 22026)
For help, click:

http://go.microsoft.com/fwlink?Prod...2&EvtSrc=MSSQLServer&EvtID=22026&LinkId=20476

Please help, and thank you for your advice.
Regards,
Tayo