Adjust phase offset in nichols chart

Hi everyone, i'm pretty new to matlab and i'm using it for university.

I have a simple problem: when i plot a nichols chart of a transfer function using the function nichols(), it sometimes happen that the plot is centered at phase 0 or -360 degrees.

To compare it with another plot i need the nichols plot centered at -180degrees. However, when i do right click>properties>adjust phase offset>-180 the phase either stays at 0 or jumps to -360 with no in between. This is the method out teacher told us to use but i've been trying for days and there's no way to have it working.

Thank you everyone for your help!