Hi Abdul,
The FAULT on DRV595 can only be OT FAULT or OC FAULT. There shouldn't be any problem when input differential voltage is 0.8V or 0.9V. Could you please check the power supply, is it always stable at 7V? Does this issue occur on only one board or all the boards? What if you change another device on the problem board?
Best regards,
Shawn Zheng