CPU usage incorrectly displayed in Swarm Agent

In the attached screen you can see a side by side view.
On the left is a slave swarm agent and pc monitor open (pc1).
On the right its a swarm agent on a PC sending the task and its monitor open (pc2).
Blue color bars representing the advance of the task on pc1 are not accurate.
The load is of full 3 processors, 75% total CPU usage.
Notheless on the pc2 you can see only one blue bar advancing.