Solenoid control over PWM
That is a clever little circuit! Is it for a diesel fuel injector or something like that? 90% duty to get the solenoid to open, 50% to hold it open. All of the components make sense to get a nice current recirculation in PWM mode then allow a 33V clip of the back EMF after switch off for a quick solenoid close. Maybe you could try slowing down the Q2 switching by adding some gate capacitance? Or provide a separate ground path from Q2 back to star ground to stop the ground bounce. I think Q1 is turning on OK because you are getting a clip of the back EMF in PWM mode.