I was having the same issue. The stored proc in itself executes but the job fails if the proc is part of job step. Finally, I managed to work around this issue by using PowerShell command in PowerShell job step:

Invoke-Sqlcmd -ServerInstance "SQLInstanceName,Port" -Database "DBName" -Query "EXEC dbo.usp_storedprocname " -AbortOnError -QueryTimeout 65535