Hi John,
Something similar is happening to me. I bought it from Banggood.
At first the sound was good on Android and Windows.
After 1st charge, there was a cracking sound on Android, while on Windows was all good.
Later that day no sound on Android, but I could see the headphones icon at the top , again windows was all good.I plugged in headphones and there was a buzzing sound like inside a tunnel.
Later that day after many restarts, No sound on Android or Windows – I could notice that there was a missing driver on Windows also, later I found that sound using bluetooth was ok Android.
I’m getting support from Banggood to do a clean install of the OS and see if the problem goes away.
Did you get a new X98 Pro? Or decided for a different model?