After further troubleshooting, i have concluded that its bluetooth v5.0 it not quite backward compatible with older bluetooth earphones and my portable JBL sound device.
I have bought a jaybird X3 to use with my mate20pro.
To add, I have found myself frastrated with the accuracy of its gps location when playing Pokemon Go. Even my 2years old samsung s7 and xiaomi phone is more accurate.
Yesterday, my wifi on mate20pro goes crazy. It intermittently unable to detect wifi source.
I'm utterly disappointed with Huawei product, so called premium phone. I have sent my problematic mate20pro for servicing.
I'm using X3 and it works totally fine.
One thing to note, when i was using my S8+ there is also breaking of sound but mainly it is because I kept my phone in my pocket. It is always worse at some location i always walked passed. It could be due to interference.
So far, mate 20 pro didn't give me any problem.
However, if i carry the phone in my hands, there is always no breaking of sound.
If it doesn't help, please go service center, there could be something wrong with the chip in phone.