Hello guys good evening.
I'm having the same issue but a little different.
I just got a banana pi m3, it is working fine, the ubuntu mate seems fine too, usb ports are ok, the logitech keyboard and mouse (all in one) was just plug and use the bluetooth and wireless connection are all in good shape but the sound is not working.
The banana is connected to my tv using hdmi cable but the different situation is that in the sound preferences does not appear any device. What should I do?? I mean the hdmi cable is working, the image seems fine too (tested on youtube and the image seemed fine) but no sound.
By the way, I'm really new to linux enviroment.
Thanks for the attention.