How to make sure QVCO output has accurate in-phase & quadrature phase clock?  I use the parallel type QVCO  (identical osc).

In my testbench A, the qvco works properly but when move to testbench B, it did not wok properly like:  no longer 90o shift, different swing amplitude. It looks like it depends on initial voltage of the oscillator.

thank you in advance.