Fixed ReportsController to not try to return a serial if the item doesn’t exist

[snipe]

We found a few cases where this was crashing the report.

[what-the-diff]

PR Summary

• Modification of postActivityReport Method
  The change has been made in a method responsible for posting activity reports. It's a technical improvement ensuring that the program doesn't attempt accessing properties of non-existing (null) items, enhancing overall stability of this part of the program.