Part Number: DRV8301
Hello.
I'm having exactly the same problem well explained in the thread "DRV8301 : Trickle Charge Circuitry and Internal Handshake".
I'm driving two DC motors with a terminal fixed to VCC and the other driven in PWM. When i drive the motor 1 the low side driver of motor 2 goes in a state where it ignores the logic input.
Even more strange is that after about 1 second of 50kHz pulses the low side driver starts to work again.