I have a custom power bank circuit that is using a CYPD3171 chip. When using an Apple PD supply of any wattage, there is a soft reset message that occurs on the CC log. This happens after the source sends Discover Identity. It appears that the sink is not responding to this message and the source times out and resets. This does not occur with other brand PD supplies. I am using the CYPD3171-24LQXQ_pb_3_3_0_1882_0_0_0_pb.hex file if this helps. I have attached a screenshot of my CC log.
According to the PD 3.0 Spec, if the source times out, Policy Engine Shall inform the Device Policy Manager of the timeout and the Policy Engine Shall transition to either the PE_SRC_Ready or PE_SNK_Ready state. It seems to be caused by the firmware of Apple PD supply. Maybe you could try to upgrade its firmware.