After Ethernet port flap: Protocol Unreachable, IP layer OK

Dear devops, after Ethernet port flap on RPi hosting Volumio 2.378. Browsers on MACbook Pro can no longer connect (existing and new sessions) to Volumio, though IP connectivity exisits (ping and ARP is OK): Destination Unreachable (Protocol unreachable) ICMP type 3 code 2. A reboot of the RPi solves the problem and connectivity to Volumio can be restored. Wireshark traces of failed and successful transactions available.
I could not find anything on the forum.
Thx, Rob.

“port flap”?

I am having a similar issue today. I thought it was my setup. In fact, if I connect a monitor and keyboard to Raspberry PI3, I can control the unit after logging on and Typing “volumio status” or “volumio play”.

Reboot of volumio makes the web UI to work , but a reboot, or restart of volumio services does not show the Web UI.