did you use the Huawei cable?I am using an Aukey 2.0 Qualcomm fast charger in my car. Sadly the car charger charges up only normally on the Mate9. The charger charges fast on my other SD phones
My own assumption is tt u need a higher output to drive close to 5A for the original cable to deliver fast charge. However now there is no car charger with 5A output.

Remember to turn on your NFC function if you wanna use.