I have updated my Huawei P20 Pro to EMUI 9,0.0.178. After the update, GPS is not working properly. After reboot, the GPS is fine, but once I stopped navigation and start a new navigation, it keeps "Looking for GPS ...". I have tried GPS test app, it just could not get GPS fix. Whenever I need to navigate, I have to reboot the phone. I am wondering anyone is facing the same issue. I have wipe the cache partition but it did not help. I do not really want to do a factory reset. However, it seems that is the last resort I have.
Maybe you can try to backup your phone with Huawei backup app through HiSense or on a micro SD card. Then reset your phone and restore your phone from backup. However, I am not sure if you can fix the issue by this way,