I recently switched to starhub and encountered the same problem. I tried a number of ways and this one finally worked for me. I first had to change my phone from Huawei mate 9 to my spare phone which is a Neffors C5. Then have to connect using USB cable. To do this go to Settings->Tethering & porting ->enable USB tethering. Then the connection is stable. Seems that connecting to laptop got this problem. But connect to hp and tablet no such issues for mate 9.