Audio output device changing at every reboot

Long story short, I tried a couple players for my Pi3+ and once got onto Volumio I threw the other memory cards away, very well done!!!

Only issue bothering me is that every time I reboot Voumio looses my default option to output through USB and I have to re-choose it before I can play music (find screenshots attached), might it be some trouble with plugins?

Thank you

Giovanni

p.s. very good job!!!

Schermata 2019-09-24 alle 19.29.37.png
Schermata 2019-09-24 alle 19.29.50.png

Hai, on my system, the amp must be ON. If the amp is off, there’s no usb output.