Ethernet interface down after reboot

I have the problem that after reboot of Volumio the network connection is not coming back. I suspect that this is related to my USB DAC, because when I switch the USB DAC off, then reboot works correctly, when the USB DAC is up and running, the the ethernet I/F is dead, so no network connection. The LEDs of the NIC are dark, so it’s not active.
So my conclusion is that the presence of the USB DAC somehow impacts the configuration of the ethernet interface. It is reproducible.
I have the following USB DAC: Project USB Box S+
I’m running Volumio on a Raspberry Pi 4, version 2.729
here’s the system information:

OS infos
Version of Volumio: 2.729
Hostname: volumio
Kernel: 4.19.86-v7l+
Governor: performance
Uptime: 0 days, 0 Hrs, 24 Minutes, 1 Seconds

Audio infos
Hw audio configured: Project USB Box S+ USB Audio 2.
Mixer type: Hardware
Number of channels: 2
Supported sample rate: 44100 48000 88200 96000 176400 192000

Board infos
Manufacturer: Raspberry Pi Foundation
Model: BCM2835 - Pi 4 Model B
Version: c03111 - Rev. 1.1
Firmware Version: Nov 29 2019 18:44:53 - aabb1fb5c19d80db268aeccd67b9f4e0f3d48a2a

CPU infos
Brand: Processor rev 3 (v7l)
Speed: 1.50Mhz
Number of cores: 4
Physical cores: 4
Average load: 1%
Temperature: 42°C

Memory infos
Memory: 4051000 Ko
Free: 3276012 Ko
Used: 774988 Ko

I don’t see anything in the logs that could give me a hint what’s going on. I wonder if you have the possibility to test this.