If you klick on my name a pop-up says one sentence about me – for your understanding.
I hope you read these two from above, if not, do it now - after this you can focus on Software - not before.
1. not enough power (read this thread to understand)
2. overheating of the SoC (heat-sink attached?)
If you have done the above, read this:
SOFTWARE support from SinoVoip
Banana is no longer Banana, read about difference between RPi and SinoVoip /Foxconn