Hi, I don't know much about win10 audio in particular, but I used to have an 18i20.
(Honestly my first advice is if you can afford it, move to a ui24r - I did, and it was expensive (though I found one on sale), but it can do everything the 18i20 can do and then like 10x more, it's easily portable, it works without a computer or over wifi, the drivers are way less frustrating, and the sound quality is much much better.)
Anyway, first of all, sometimes the 18i20 wouldn't connect to its control panel and it would need rebooting. Sometimes a computer reboot would fix it. Sometimes the USB connection came off the back just enough to fail!
Much like I just posted about in another thread, often some software is trying to speak 44.1KHz and some is 48KHz. The 18i20 tried to speak 96KHz a lot of the time. If the speed of the software and the speed of the control panel were different, it would go totally silent and not explain why in any way.
You might also have luck using Voicemeeter Banana to mix because that could take some of the frustrating 18i20 interface out of the situation. Though I also remember painstakingly going through every channel on the 18i20 and setting the outputs and inputs so that Track 1 = Input 1 = Output 1 etc, all in alignment, because I don't think there was a default or pushbutton way to set that up. (On the ui24r, there's literally a single button to do that. :) )
