The Congestion field toggles the
-congestion Tcl switch ON and OFF.
Select the Minimum congestion level option to specify the minimum congestion to show router congestion in the design. The default minimum congestion level is 5 if not specified. The value must be between 3 and 8.
Equivalent Tcl option:
-min_congestion_level). In that case, re-run the command with a lower threshold (values between 3 and 8).