AA on my new Huawei (Android 8) would not connect at first. My old P9 (Android 7) was fine. Then I managed to get it to connect somehow but the connection was unreliable. Recently an AA update came out and Huawei also had an OS update. It is much better now, but stupidly cable sensitive. The only one that consistently works is a Samsung micro USB cable with the Huawei micro USB to USB C adapter.
This is a widespread issue even affecting Pixels.
There also was a SEAT Tech advisory to allow the head unit to boot up before connecting your phone.
Make sure you have the latest phone and AA update, 3.3.582054-release.
PS. I should add, that the USB ports seem to shut down for some time when trying to sort these issues out. I've had it go dead, only to connect fine an hour later.