Sony HAP-Z1ES and Denafrips DAC

I bought the Sony HAP-Z1ES a few years ago. It has the latest firmware dated Feb 2017. A few days ago I received Denafrips Terminator DAC which was ordered a month ago. It was connected to the Sony HAP-Z1ES using USB connection.

With both Sony HAP-Z1ES and Terminator turned on, when Terminator input is switched to USB, Sony HAP-Z1ES shows "An unsupported USB device has been connected". But the Sony analog output is turned off and data is indeed sent to the external DAC, producing sound.

I’ve tried rolling back Sony Z1ES firmware to the previous version and it behaves exactly the same.

Before I ordered Denafrips Terminator DAC, I’ve tested Sony HAP-Z1ES with Oppo UDP-205 as an external USB DAC and it works flawlessly without any errors. So I assume the Sony will work with another DAC.

Also, occasionally when jumping tracks or changing folder, Terminator DAC produces very weird and wrong sound. It does not happen all the time. When it happened, jumping to the next track or restarting the existing track clears the problem.

I would like to hear experience of other Sony HAP-Z1ES users when using external DAC, especially the Denafrips DAC brand, if you see similar problem. Thank you so much.
I can't help on the first point but on the second I've seen the same thing with my HAP-Z and Marantz SA8005.  It happens occasionally when the bit rate changes.  Like you say, changing tracks again or hitting pause/play sets it right.  
Anwar, I can't respond to your questions, and I don't want to divert your thread, but would you be willing to describe the differences you've heard between using the HAP-Z1ES' DAC without the Denafrips and with the Denafrips?  Thanks.

@jimcrane, sure I plan to share my listening experience after the Terminator has nicely broken in and after I have received USB cable from Curious Cable, Australia.  Currently I am using budget USB cable, AudioQuest Forest.  I've also tried Supra USB cable and it does make a difference.  I prefer the Forest.

My preliminary impression after 4 days, the difference is huge.  With the Terminator, I am drawn into the music as the it sounds so natural and analog-like, bigger sound stage, and can hear more details without being harsh.  Due to that, I have to rediscover my CD collection.  I ended up sleeping late a few nights as I feel so relaxed listening to it.  More coming later....