After reading through it looks like you have issues with your Internet, rather than issue with Mi TV. We have tested Mi TV with Soundbar, while playing content from Internet (at Mi Home). The bandwidth at Mi Home was good, and we found buffer only when playing 4K videos.

It would be better to check your internet than blaming the device.

Also you can do a bit of search about Bluetooth and Wifi modules used in devices. They are not same, there will be different components connected to the system. So one causing trouble to other is false information.