Code:sp sp start=0 stop=3G step=1G
This statement of Cadence Spectre generates s-parameters at freq=0, 1GHz, 2GHz and 3GHz.
Try plot S11 in Smith Chart of Cadence ViVA.
Change plot with symbol and without line.
You can confirm four points.
Move cursol to each point and confirm frequency by tracking information.
You see 0, 0, 1GHz and 2GHz.
There is no last frequency, 3GHz.
Have you known such bug of Smith Chart of Cadence ViVA ?