Lumin U2 „USB to DAC” port stopped working

Hi, I was using Lumin U2 with Mcintosh 8900 integrated (DA1 DAC) through USB direct port, but since yesterday it stopped working. I tried resetting everything, power cycling, disconnecting and changing cables and no sound. I can get sound from the middle USB port, Lumin and the DAC is working. Any advice before taking it for the repair?

Regards, Adam

Update: Both left and middle USB ports are connecting with the DAC and playing music

There has been a firmware update (V18) in the last few days, have you loaded it/checked your U2 settings are still correct?

Note. only applicable if you are in Taiwan, Hong Kong, Japan, Singapore, and Malaysia.

I’m in Europe. My Firmware is 17.3. I have double checked all the settings and done factory reset in software and using the reset button procedure.

Please check PM.