CDT value is empty while calling a process model from Interface using Start Process

Hi All,

I am invoking a process model from Interface using start process in 'Submit' button.

Process model is being invoked while clicking on 'Submit' button, but CDT parameter is always appearing as null.

While testing the interface manually I am getting CDT values in process model. While invoking the interface from site CDT values are empty.

Please help on it and below are the screenshots for your reference.

Interface code:

a!columnLayout(
contents: {
a!buttonArrayLayout(
buttons: {
a!buttonWidget(
label: "Submit",
saveInto: a!startProcess(
processModel: cons!CU_Interview_Process_Model_Constant,
processParameters: {
Cu_Interview: ri!Cu_Interview,
test: " ABCD "
},
onSuccess: null,
onError: null
),
submit: true,
style: "PRIMARY"
)
},
align: "START"
)

Process Model:

Process Model Variables:

 Process model is being invoked but CDT variable is empty. Modify Variable is not appearing for CDT .

While testing interface values are appearing in rule,

Just FYI, a!local variables has been used in starting of the expression