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Different values of "Output:Variable" and "EnergyManagementSystem:OutputVariable" for the same Sensor in EnergyPlus

I am using EMS to compute an intermediate value based on the available sensors. To check that the correct values are used in the EMS calculations, I created customized EMS outputs for those sensors and compared them with their values produced in the ESO file. For example, one of the sensors is the System Node Wetbulb Temperature of the Air Loop Demand Side Outlet as follows:

Actual sensor reading:

Output:Variable,
        Air Loop Demand Side Outlet,  !- Key Value
        System Node Wetbulb Temperature,  !- Variable Name
        timestep;                  !- Reporting Frequency

EMS sensor reading definition and it custom output:

Output:Variable,
        *,                       !- Key Value
        AirLoopWetbulb_Temperature_EMS,                !- Variable Name
        timestep;                  !- Reporting Frequency

    EnergyManagementSystem:Sensor,
        AirLoopWetbulb_Temperature,                !- Name
        Air Loop Demand Side Outlet,  !- Output:Variable or Output:Meter Index Key Name
        System Node Wetbulb Temperature;  !- Output:Variable or Output:Meter Name

    EnergyManagementSystem:OutputVariable,
        AirLoopWetbulb_Temperature_EMS,                !- Name
        AirLoopWetbulb_Temperature,                !- EMS Variable Name
        Summed,                  !- Type of Data in Variable
        !Averaged,                  !- Type of Data in Variable
        ZoneTimeStep ;           !- Update Frequency

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Is there a way to eliminate or minimize this error? I tried different EMS Program Calling options as follows:

    EnergyManagementSystem:ProgramCallingManager,
        For EMS Run , !- Name
        BeginTimestepBeforePredictor,  !- EnergyPlus Model Calling Point
        !AfterPredictorBeforeHVACManagers
        !EndOfZoneTimestepAfterZoneReporting
        !EndOfZoneTimestepBeforeZoneReporting
        EMSProgram1;        !- Program Name 1

Thank you.