DRV8302: GH_x and SH_x output sawtooth-like 1.8v voltage

Hi Experts,

Good day. I have this waveform issue from client using our gate driver IC.

GH_x and SH_x output sawtooth-like 1.8v voltage when its INH_x and INL_x are both LOW, but their Low level output is 0v when INH_x and INL_x have different PWM level. I have attached the waveform of GH and SH signal and the blue is GH and SH, the red is its INH.

Any thoughts why it looks like this?

Regards,
Archie A.