Cannot connect to WiFi when using USB DAC

Hi,
I"m a newbie to Volumio and am having problems connecting to WiFi.
I have a RPi 3 with a hifiberry digi+ Pro hat. Running Volumio version 3.324.
I also have an external USB dac that I would prefer to use instead of the hat. However when I turn off the I2S DAC option in audio output, volumio no longer connects to WiFi. If I turn it on and select the hifiberry digi+ Pro then it connects.
There is no option to connect to the USB dac when I2S is on, so I can’t leave it on.
To be clear, it works fine with an ethernet cable and sometimes appears to connect
To WiFi when the ethernet cable is plugged in, but if I disconnect the cable it no longer works, even after a restart.
I have tried reinstalling volumio but its the same.
Does anybody have any idea what could be wrong or is it a mistake I am making.

Log : http://logs.volumio.org/volumio/hhso05m.html
Thanks for any help