Volumio+PiZero+Justboom DAC OTG ethernet connection

I have a good running system of Volumio on a Pi Zero with a Justboom DAC phat to provide sound for two passive speaker. Since i do not really like WIFI around, i prefer to connect everything to LAN via ethernet cables. For this i use the OTG cable provided with the Zero and normal USB to Ethernet adapter. I works well but i have still have two issues:

  1. if i connect and power up everything, the networks connection does not work by default. I need to power up the system without the OTG, then connect the OTG cable, than a few seconds later the USB Ethernet Adapter, and then connect the ethernet cable. Then everything works fine.
  2. if i disconnect the ethernet cable from the running, network connected system, upon reconnecting the ethernet cable the network connect is gone and need restart the whole start up process described above.
    Using the Waveshare Ethernet pHat does not have this issue, works fine. I know i should use that… But i would like to understand.
    Seems to me that OTG connection needs to renewed, restarted, but how do i do that? Or what else do i need to do to get this solved.
    thank you