Thanks, for answer!

Yes, ID value exist. 

Before the appearance of the form, ID_Carriage is initialized. At the time of the launch of activity and DT, ID_Carriage also exists. It does not change value.

Thanks for the answer!
Figure 1 shows the context of the Data-Carriage page.
Figure 2 shows the content sections of the RSTempSection. There is a table that displays data from a Data-CarrierList.
Figure 3 shows the activity that, when called, clears the CarrierList. It is worth noting that this activity is in post-processing. The remaining activities that are inside the section do not clear the contents of CarrierList.
Figure 4 - Tracer before step 1.
Figure 5 - Tracer after performing step 1.
Figure 6 is the main view of D_getCarriageList.
Figure 7 - Parameters page in D_getCarriageList.
Figure 8 - passing parameters to report definition.
Figure 9 - report definition.