STEP: A small EMC puzzle

Part 1: The initial condition

The STEP unit was powered, and configured to run in "nominal" science mode, which includes creation and sending of HK telemetry, and data product processing. What appeared on the scope during conducted emission, differential transition mesaurement was the following picture:

The requirement is that the peaks/spikes in this test do not exceed a peak-to-peak current of 20mA. The highest peak exceeds that by roughly 5mA. So this is a non-compliance!

Do you know what causes those three peaks? Take a look at the time between the peaks. What does STEP do (in its current configuration) which could correspond to this pattern?

Part 2: Searching for clues