Hi, I have recently started getting this error when running PSS:

"V(out) is too small to reliably detect the period of the
oscillator. This may be because nodes with insignificant signal levels
were chosen, or it may be because the oscillator was never properly
started."

I can resolve it by changing the initial guess of the fundamental frequency (even by 1MHz) but I don't understand why? There is an initial condition on this node to start the oscillation and transient starts ok.  Any insight would be appreciated as I am not too familiar with how the PSS simulator actually works...