Proxy Account Error

Hi,
I have created a credential crdentailID with identity of my ID. I have sysadming access. I created a proxy Account (ProxyAC) using credetnail ID crdentailID.
I have enabled SQL agent job with run as: ProxyAC. I'm using Correct ID and password for Credetial IDentity.
I'm getting the below error

Unable to start execution of step 1 (reason: Error authenticating proxy DOM\MyID, system error: Logon failure: unknown user name or bad password.). The step failed.

Is there any solution for this?.